Fix map move pixels function

Thanks to @dalkon for this.
Bind g_minimap.updateTile to lua

This is needed to update tile removals from minimap widget.
Tiny fix for movePixels
Take out debug message
Increase maximum move offset to be 64 instead of 32
Fixup movePixels a little bit

Thanks to @dalkon for dis.
Only request tile cache to be updated once for both x & y