Add links to the new refs page from summary page

If either branches or tags are filtered on the summary page, add a link to
refs/heads and/or refs/tags right below the last branch/tag.

Signed-off-by: Lars Hjemli <hjemli@gmail.com>

cgit.h

@@ -236,6 +236,8 @@ extern void cgit_log_link(char *name, char *title, char *class, char *head,
 			  char *rev, char *path, int ofs);
 extern void cgit_commit_link(char *name, char *title, char *class, char *head,
 			     char *rev);
+extern void cgit_refs_link(char *name, char *title, char *class, char *head,
+			   char *rev, char *path);
 extern void cgit_snapshot_link(char *name, char *title, char *class,
 			       char *head, char *rev, char *archivename);
 extern void cgit_diff_link(char *name, char *title, char *class, char *head,