Add completion for git-svn mkdirs,reset,and gc

Signed-off-by: Robert Zeh <robert.a.zeh@gmail.com>
Acked-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

contrib/completion/git-completion.bash

@@ -2022,7 +2022,7 @@ _git_svn ()
 		init fetch clone rebase dcommit log find-rev
 		set-tree commit-diff info create-ignore propget
 		proplist show-ignore show-externals branch tag blame
-		migrate
+		migrate mkdirs reset gc
 		"
 	local subcommand="$(__git_find_on_cmdline "$subcommands")"
 	if [ -z "$subcommand" ]; then
@@ -2069,7 +2069,7 @@ _git_svn ()
 			__gitcomp "--stdin $cmt_opts $fc_opts"
 			;;
 		create-ignore,--*|propget,--*|proplist,--*|show-ignore,--*|\
-		show-externals,--*)
+		show-externals,--*|mkdirs,--*)
 			__gitcomp "--revision="
 			;;
 		log,--*)
@@ -2106,6 +2106,9 @@ _git_svn ()
 				--no-auth-cache --username=
 				"
 			;;
+		reset,--*)
+			__gitcomp "--revision= --parent"
+			;;
 		*)
 			COMPREPLY=()
 			;;