Flag one time placement

Hey guys,

I added the flag to the 'Gaia' tab. Also, you can only place it once. Right now it can take any texture but its necessary to manually change on the initFlag function. The size of the flag can also be passed to the initFlag function.
So for the final Flag status symbol is missing:
- Select texture before placement
- Change texture after placement
- Change size according to position on leaderboard or just points
- Change the placement position 
- Remove flag
- Check collisions

I was planning to do more before tomorrow, but I complety forgot to update the flag branch before doing the changes, and in the end I lost time again understanding the changes on the Gui that were made in the meanwhile. I feel stupid xD Sorry guys.