repolist: add owner-filter

This allows custom links to be used for repository owners by
configuring a filter to be applied in the "Owner" column in the
repository list.

ui-repolist.c

@@ -307,13 +307,19 @@ void cgit_print_repolist()
 		html_link_close();
 		html("</td><td>");
 		if (ctx.cfg.enable_index_owner) {
-			html("<a href='");
-			html_attr(cgit_rooturl());
-			html("?q=");
-			html_url_arg(ctx.repo->owner);
-			html("'>");
-			html_txt(ctx.repo->owner);
-			html("</a>");
+			if (ctx.repo->owner_filter) {
+				cgit_open_filter(ctx.repo->owner_filter);
+				html_txt(ctx.repo->owner);
+				cgit_close_filter(ctx.repo->owner_filter);
+			} else {
+				html("<a href='");
+				html_attr(cgit_rooturl());
+				html("?=");
+				html_url_arg(ctx.repo->owner);
+				html("'>");
+				html_txt(ctx.repo->owner);
+				html("</a>");
+			}
 			html("</td><td>");
 		}
 		print_modtime(ctx.repo);