Git.pm: Implement Git::version()

Git::version() returns the Git version string.

Signed-off-by: Petr Baudis <pasky@suse.cz>
Signed-off-by: Junio C Hamano <junkio@cox.net>

perl/Git.xs

@@ -23,6 +23,16 @@ PROTOTYPES: DISABLE
 # /* TODO: xs_call_gate(). See Git.pm. */
 
 
+const char *
+xs_version()
+CODE:
+{
+	RETVAL = GIT_VERSION;
+}
+OUTPUT:
+	RETVAL
+
+
 const char *
 xs_exec_path()
 CODE: