allow selective enabling of snapshots

snapshot configuration parameter now can be a
 space/slash/comma/colon/semicolon/pipe-separated list of snaphot suffixes as
 listed in ui-snapshot.c

Signed-off-by: Michael Krelin <hacker@klever.net>

ui-commit.c

@@ -196,7 +196,7 @@ void cgit_print_commit(char *hex)
 	}
 	if (cgit_repo->snapshots) {
 		html("<tr><th>download</th><td colspan='2' class='sha1'>");
-		cgit_print_snapshot_links(cgit_query_repo,hex);
+		cgit_print_snapshot_links(cgit_query_repo,hex,cgit_repo->snapshots);
 		html("</td></tr>");
 	}
 	html("</table>\n");