cg-help: dynamically list commands

Use code from the make-cogito-asciidoc script to make the command listing dynamic and hopefully always up-to-date by grepping the USAGE strings.

---

 cg-commit |    2 +-
 cg-help   |   47 +++++++++++++++++++++--------------------------
 2 files changed, 22 insertions(+), 27 deletions(-)

@@ -72,7 +72,7 @@
 # EDITOR::
 #	The editor used for entering revision log information.
 
-USAGE="cg-commit [-mMESSAGE]... [-C] [-e | -E] [FILE]..."
+USAGE="cg-commit [-mMESSAGE]... [-C] [-e | -E] [FILE]... < MESSAGE"
 
 . ${COGITO_LIB}cg-Xlib
 

Jonas Fonseca