Start systematic improvements of error reporting.

So far, this covers all WARNINGs related to the prologue.

1) hierarchical naming of MANDOCERR_* constants
2) mention the macro name in messages where that adds clarity
3) add one missing MANDOCERR_DATE_MISSING msg
4) fix the wording of one message related to the man(7) prologue

Started on the plane back from Ottawa.

1 files changed, 1 insertions, 1 deletions

diff --git a/read.c b/read.c
index 67209f8d..482af0db 100644
--- a/read.c
+++ b/read.c
@@ -93,7 +93,7 @@ static	const char * const	mandocerrs[MANDOCERR_MAX] = {
 	"generic warning",
 
 	/* related to the prologue */
-	"no title in document",
+	"no TH macro in document",
 	"document title should be all caps",
 	"unknown manual section",
 	"unknown manual volume or arch",