git svn: add gc command

Add a git svn gc command that gzips all unhandled.log files, and
removes all index files under .git/svn.

Signed-off-by: Robert Allan Zeh <robert.a.zeh@gmail.com>
Signed-off-by: Eric Wong <normalperson@yhbt.net>
diff --git a/Documentation/git-svn.txt b/Documentation/git-svn.txt
index 10af599..068aa58 100644
--- a/Documentation/git-svn.txt
+++ b/Documentation/git-svn.txt
@@ -338,6 +338,10 @@
 	Shows the Subversion externals.  Use -r/--revision to specify a
 	specific revision.
 
+'gc'::
+	Compress $GIT_DIR/svn/<refname>/unhandled.log files in .git/svn
+	and remove $GIT_DIR/svn/<refname>index files in .git/svn.
+
 'reset'::
 	Undoes the effects of 'fetch' back to the specified revision.
 	This allows you to re-'fetch' an SVN revision.  Normally the