IT COMPILES. Yay!
Added game library. It handles the game logic. Well, it handles the state changes in the system.
Added function calls to game library from communication.
Modified receiver library so that receiver_listenSignal returns the number it received.
Modified storage library to add a function that gets the unsent entries so they can be sent before program end.
Modified enemy library to make it return the number of the enemy that it found when checking if it exists.
Modified receiver library to make use of function pointer for the interrupt.

On a personal note: I feel like a badass right now. I feel like today I've made a lot of progress! :D

Signed-off-by: Cesar Andreu <cesarandreu@gmail.com>
I forgot to actually uncomment the game library function calls in communication. Fixed it now.

Signed-off-by: Cesar Andreu <cesarandreu@gmail.com>