update MBTiles source for upstream protocol changes

@@ -44,6 +44,8 @@
     RMFractalTileProjection *tileProjection;
 }
 
+@synthesize cacheable = _cacheable, opaque = _opaque;
+
 - (id)initWithTileSetURL:(NSURL *)tileSetURL
 {
 	if ( ! (self = [super init]))
@@ -63,6 +65,9 @@
         [db setShouldCacheStatements:YES];
     }];
 
+    self.cacheable = NO;
+    self.opaque = YES;
+
 	return self;
 }
 
@@ -130,6 +135,11 @@
     return image;
 }
 
+- (BOOL)tileSourceHasTile:(RMTile)tile
+{
+    return YES;
+}
+
 - (NSString *)tileURL:(RMTile)tile
 {
     return nil;