git-svn: print out the SVN library version in --version, too

This could be useful in finding new problems and helping users
debug.

Signed-off-by: Eric Wong <normalperson@yhbt.net>
Signed-off-by: Junio C Hamano <junkio@cox.net>
diff --git a/git-svn.perl b/git-svn.perl
index 0ef13b2..a772ce8 100755
--- a/git-svn.perl
+++ b/git-svn.perl
@@ -216,7 +216,7 @@
 }
 
 sub version {
-	print "git-svn version $VERSION\n";
+	print "git-svn version $VERSION (svn $SVN::Core::VERSION)\n";
 	exit 0;
 }