Added Inventory

Inventory System.

I've added documentation to the "client/inventory" code that expains things. everything still has the mf_* prefix (my obfuscator uses it).

I used my mf_comile function for most of the client_compiles... when running #define DEBUG true in init.sqf (the main mission init.sqf" it will dynamically recompile the sqf files each call, so much much less restarting the mission when changing something small. if you set DEBUG false then it will compileFinal the functions instead, so for release  please dont forget :P