ui-tree: unify with ui-view, use path to select tree/blob

This teaches ui-tree to show both trees and blobs, thereby making ui-view
superfluous. At the same time, ui-tree is extended to honour the specified
path instead of requiering a tree/blob sha1.

cgit.c

@@ -97,14 +97,11 @@ static void cgit_print_repo_page(struct cacheitem *item)
 			       cgit_query_path, 1);
 		break;
 	case CMD_TREE:
-		cgit_print_tree(cgit_query_head, cgit_query_sha1, cgit_query_path);
+		cgit_print_tree(cgit_query_sha1, cgit_query_path);
 		break;
 	case CMD_COMMIT:
 		cgit_print_commit(cgit_query_head);
 		break;
-	case CMD_VIEW:
-		cgit_print_view(cgit_query_sha1, cgit_query_path);
-		break;
 	case CMD_DIFF:
 		cgit_print_diff(cgit_query_head, cgit_query_sha1, cgit_query_sha2,
 				cgit_query_path);