git commit: Allow editing on all occasions.

Sometimes it may be handy to be able to edit messages that come
from somewhere other than an existing commit.

This makes 'git commit -F <file> -e' to start editor with the initial
log message contents taken from <file>.
Signed-off-by: NJunio C Hamano <junkio@cox.net>

git-commit-script

@@ -64,6 +64,9 @@ do
     use_commit="$1"
     no_edit=t
     shift ;;
+  -e|--e|--ed|--edi|--edit)
+    no_edit=
+    shift ;;
   -s|--s|--si|--sig|--sign|--signo|--signof|--signoff)
     signoff=t
     shift ;;