Rework textures

[spectraldesign]

Right now you have separate textures for every flag, and separate textures for every player and every possible rotation of that player. Each texture also has the ground texture implemented in the background. It would be better if this was done using alpha channels and drawn over a fully tiled floor, and to rotate the texture in the program as opposed to loading a new texture when rotating.

High priority:

• Make use of alpha channel png for overlapping objects (players, flags, maybe holes and walls as well) with ground
• Rotate textures in program, would allow for much fewer textures in total

Low priority:

• Render numbers using text on top of texture instead of text being a part of texture (flags could then be one singular texture)

[spectraldesign]

Can use Sprite.rotate90(boolean clockwise); for rotating textures, but should fix movement logic first, ref Issue#15, since it would currently mess up player rotation

[spectraldesign]

Used Sprite.rotate90(boolean clockwise); for rotating textures. Changed render to render the whole ground first, then other objects on top of that, using png with transparent background.

[spectraldesign]

Need to implement custom font before this, which may or may not happen depending on time limit. Using the default font will look too pixelated.