Improved implementation of Stock room

Modified the LoadResources class nested in Resources (written by JP) to
become the Stock class.

Modified the removeFood, removeLarvae, removeStone and removeEarth
methods to prevent the number of resources from becoming negative.

Example of usage of the stock class is shown in TestStock.java
Merged with JP's stock room implementation
Merge branch 'master' of https://github.com/r0ck5tar/Myrmes

Conflicts:
	src/antColony/Resources.java