git-gui: Support more git version notations.

Recently the msysgit repository has got a '1.6.1-msysgit1'
tag, which, when used to build the git version, is not
handled gracefully by the git-gui version code.

This patch changes the regular expressions to fix it, and
removes the hardcoded 'rc' string. Now git-gui can accept
a version tail like '.foo123.GIT.bar.456.7.g89ab'

Signed-off-by: Alexander Gavrilov <angavrilov@gmail.com>
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

git-gui.sh

@@ -769,9 +769,9 @@ if {![regsub {^git version } $_git_version {} _git_version]} {
 set _real_git_version $_git_version
 regsub -- {[\-\.]dirty$} $_git_version {} _git_version
 regsub {\.[0-9]+\.g[0-9a-f]+$} $_git_version {} _git_version
-regsub {\.rc[0-9]+$} $_git_version {} _git_version
+regsub {\.[a-zA-Z]+\.?[0-9]+$} $_git_version {} _git_version
 regsub {\.GIT$} $_git_version {} _git_version
-regsub {\.[a-zA-Z]+\.[0-9]+$} $_git_version {} _git_version
+regsub {\.[a-zA-Z]+\.?[0-9]+$} $_git_version {} _git_version
 
 if {![regexp {^[1-9]+(\.[0-9]+)+$} $_git_version]} {
 	catch {wm withdraw .}