Major rewrite of RCS backends. RCS now represented as a class.

Lots of changes and just one commit.  This started with bug
dac91856-cb6a-4f69-8c03-38ff0b29aab2, when I noticed that new bugs
were not being added appropriately with the Git backend.  I'd been
working with Git trouble before with bug
0cad2ac6-76ef-4a88-abdf-b2e02de76f5c, and decided things would be
better off if I just scrapped the current RCS architecture and went to
a more object oriented setup.  So I did.  It's not clear how to add
support for an RCS backend:
 * Create a new module that
   - defines an inheritor of rsc.RCS, overriding the _rcs_*() methods
   - provide a new() function for instantizating the new class
   - defines an inheritor of rcs.RCStestCase, overiding the Class attribute
   - defines 'suite' a unittest.TestSuite testing the module
 * Add your new module to the rest in rcs._get_matching_rcs()
 * Add your new module to the rest in libbe/tests.py
Although I'm not sure libbe/tests.py is still usefull.

The new framework clears out a bunch of hackery that used to be
involved with supporting becommands/diff.py.  There's still room for
progress though.  While implementing the new verision, I moved the
testing framework over from doctest to a doctest/unittest combination.
Longer tests that don't demonstrate a function's usage should be moved
to unittests at the end of the module, since unittest has better
support for setup/teardown, etc.

The new framework also revealed some underimplented backends, most
notably arch.  These backends have now been fixed.

I also tweaked the test_usage.sh script to run through all the backends
if it is called with no arguments.

The fix for the dac bug turned out to be an unflushed file write :p.

1 files changed, 21 insertions, 0 deletions

diff --git a/.be/bugs/dac91856-cb6a-4f69-8c03-38ff0b29aab2/comments/1182d8e6-5e87-4d0a-b271-c298c36bbc21/values b/.be/bugs/dac91856-cb6a-4f69-8c03-38ff0b29aab2/comments/1182d8e6-5e87-4d0a-b271-c298c36bbc21/values
new file mode 100644
index 0000000..3d4f044
--- /dev/null
+++ b/.be/bugs/dac91856-cb6a-4f69-8c03-38ff0b29aab2/comments/1182d8e6-5e87-4d0a-b271-c298c36bbc21/values
@@ -0,0 +1,21 @@
+
+
+
+Content-type=text/plain
+
+
+
+
+
+
+Date=Wed, 19 Nov 2008 01:12:37 +0000
+
+
+
+
+
+
+From=John Doe <jdoe@example.com>
+
+
+