Merged be.restructure, major internal reorganization.

Added a bunch of classes to make the commands, user interfaces, and
storage backends more abstract and distinct.  This should make it much
easier to extend and maintain BE.

Features:
 * Directory restructured:
   becommands/ -> libbe/commands
   submods sorted by functionality.
 * Lots of new classes:
   Option, Argument, Command
   InputOutput, StorageCallbacks, UserInterface
   Storage
 * Consolidated ID handling in libbe.util.id
 * Transitioned VCS backends for Python-based VCSs from subprocess
   calss to internal python calls.

Plus the user-visible changes:
 * New bugdir/bug/comment ID format replaces old bug:comment format.
 * Deprecated support for `be diff` on Arch and Darcs <= 2.3.1.  A new
   backend abstraction (Storage) makes the former implementation
   ungainly.
 * Improved command completion.
 * Removed commands close, open, email_bugs, 
 * Flipped some arguments
   `be assign BUG-ID [ASSIGNEE]` -> `be status ASSIGNED BUG-ID ...`
   `be severity BUG-ID SEVERITY` -> `be severity SEVERITY BUG-ID ...`
   `be status BUG-ID STATUS` -> `be status STATUS BUG-ID ...`

In the merge:
  * Added 'commit' to list of pagerless commands.
  * Updated doc/README.dev

See
#bea86499-824e-4e77-b085-2d581fa9ccab/1100c966-9671-4bc6-8b68-6d408a910da1#
for a discussion of why the changes were made and some of the
difficulties en-route.

5 files changed, 87 insertions, 0 deletions

diff --git a/.be/bea86499-824e-4e77-b085-2d581fa9ccab/bugs/51930348-9ccc-4165-af41-6c7450de050e/comments/d304f93b-faf2-477e-9ff8-c77e301fd9f9/body b/.be/bea86499-824e-4e77-b085-2d581fa9ccab/bugs/51930348-9ccc-4165-af41-6c7450de050e/comments/d304f93b-faf2-477e-9ff8-c77e301fd9f9/body
new file mode 100644
index 0000000..34d37e5
--- /dev/null
+++ b/.be/bea86499-824e-4e77-b085-2d581fa9ccab/bugs/51930348-9ccc-4165-af41-6c7450de050e/comments/d304f93b-faf2-477e-9ff8-c77e301fd9f9/body
@@ -0,0 +1,30 @@
+Added libbe/upgrade.py to handle upgrading on-disk bugdirs.
+
+When upgrade.BUGDIR_DISK_VERSION changes, a series of Updater
+classes handle the upgrade.  For example, if 
+  BUGDIR_DISK_VERSIONS = ["v1", "v2", "v3"]
+and the on-disk version is "v1", you should have defined classes
+  class Upgrade_1_to_2 (Upgrader):
+      initial_version = "v1"
+      final_version = "v2"
+      def _upgrade():
+          ....
+  class Upgrade_2_to_3 (Upgrader):
+      initial_version = "v2"
+      final_version = "v3"
+      def _upgrade():
+          ....
+and added them to upgraders:
+  upgraders = [Upgrade_1_to_2, Upgrade_2_to_3]
+If the on-disk version is v2, then only Upgrade_2_to_3.upgrade() is
+run.  If the on-disk version is v1, then Upgrade_1_to_2.upgrade() is
+run, followed by Upgrade_2_to_3.upgrade().
+
+You can optionally define shortcut upgrades (e.g. Upgrade_1_to_3) for
+efficiency or to avoid data loss.
+
+This upgrade occurs during BugDir.load(), which is called by
+BugDir.__init__(from_disk=True), before any processing of the on-disk
+data except for the access of .be/version to determine if an upgrade
+was necessary.
+
diff --git a/.be/bea86499-824e-4e77-b085-2d581fa9ccab/bugs/51930348-9ccc-4165-af41-6c7450de050e/comments/d304f93b-faf2-477e-9ff8-c77e301fd9f9/values b/.be/bea86499-824e-4e77-b085-2d581fa9ccab/bugs/51930348-9ccc-4165-af41-6c7450de050e/comments/d304f93b-faf2-477e-9ff8-c77e301fd9f9/values
new file mode 100644
index 0000000..b296bff
--- /dev/null
+++ b/.be/bea86499-824e-4e77-b085-2d581fa9ccab/bugs/51930348-9ccc-4165-af41-6c7450de050e/comments/d304f93b-faf2-477e-9ff8-c77e301fd9f9/values
@@ -0,0 +1,11 @@
+Author: W. Trevor King <wking@drexel.edu>
+
+
+Content-type: text/plain
+
+
+Date: Mon, 31 Aug 2009 16:29:50 +0000
+
+
+In-reply-to: f1479ecf-4154-4cd4-bbd6-0ed6275b9f98
+
diff --git a/.be/bea86499-824e-4e77-b085-2d581fa9ccab/bugs/51930348-9ccc-4165-af41-6c7450de050e/comments/f1479ecf-4154-4cd4-bbd6-0ed6275b9f98/body b/.be/bea86499-824e-4e77-b085-2d581fa9ccab/bugs/51930348-9ccc-4165-af41-6c7450de050e/comments/f1479ecf-4154-4cd4-bbd6-0ed6275b9f98/body
new file mode 100644
index 0000000..372a655
--- /dev/null
+++ b/.be/bea86499-824e-4e77-b085-2d581fa9ccab/bugs/51930348-9ccc-4165-af41-6c7450de050e/comments/f1479ecf-4154-4cd4-bbd6-0ed6275b9f98/body
@@ -0,0 +1,16 @@
+There is no obvious means of using
+".be/version"/"libbe.bugdir.TREE_VERSION_STRING".  In the past I've
+worked around this by keeping all the disk-reading backwards
+compatible (e.g. homemade mapfile -> YAML, the "From" hack in
+libbe.comment.Comment.load_settings, possibly others).  However, this
+is not the road to easily maintainable code.
+
+Most projects only need to maintain backwards compatibility with the
+last few versions of their disk cache, to allow users an easy upgrade
+path.  The difficulties come with "be diff", which must be able to
+read _every_ disk-image of the bugdir ever committed into something
+comparible with the current cutting edge.  This makes sweeping changes
+very difficult.  VCSs themselves avoid this by never showing their
+disk-cache to another program, but we've shown ours to the VCS, and
+it's difficult (or impossible, depending on the VCS) to change history
+to match the current format.
diff --git a/.be/bea86499-824e-4e77-b085-2d581fa9ccab/bugs/51930348-9ccc-4165-af41-6c7450de050e/comments/f1479ecf-4154-4cd4-bbd6-0ed6275b9f98/values b/.be/bea86499-824e-4e77-b085-2d581fa9ccab/bugs/51930348-9ccc-4165-af41-6c7450de050e/comments/f1479ecf-4154-4cd4-bbd6-0ed6275b9f98/values
new file mode 100644
index 0000000..3d4d9df
--- /dev/null
+++ b/.be/bea86499-824e-4e77-b085-2d581fa9ccab/bugs/51930348-9ccc-4165-af41-6c7450de050e/comments/f1479ecf-4154-4cd4-bbd6-0ed6275b9f98/values
@@ -0,0 +1,8 @@
+Author: W. Trevor King <wking@drexel.edu>
+
+
+Content-type: text/plain
+
+
+Date: Sun, 16 Aug 2009 19:07:06 +0000
+
diff --git a/.be/bea86499-824e-4e77-b085-2d581fa9ccab/bugs/51930348-9ccc-4165-af41-6c7450de050e/values b/.be/bea86499-824e-4e77-b085-2d581fa9ccab/bugs/51930348-9ccc-4165-af41-6c7450de050e/values
new file mode 100644
index 0000000..75a191c
--- /dev/null
+++ b/.be/bea86499-824e-4e77-b085-2d581fa9ccab/bugs/51930348-9ccc-4165-af41-6c7450de050e/values
@@ -0,0 +1,22 @@
+creator: W. Trevor King <wking@drexel.edu>
+
+
+extra_strings:
+- BLOCKS:22b6f620-d2f7-42a5-a02e-145733a4e366
+- BLOCKS:427e0ca7-17f5-4a5a-8c68-98cc111a2495
+
+
+reporter: W. Trevor King <wking@drexel.edu>
+
+
+severity: minor
+
+
+status: fixed
+
+
+summary: Upgrade path for on-disk representation
+
+
+time: Sun, 16 Aug 2009 19:05:59 +0000
+