New loadout approach

[Casperento]

Changes proposed in this pull request:

• fn_startLoadout.sqf refact. to use setUnitLoadout

• Config_Loadouts.hpp reworked to support Arma 3 Unit Loadouts format

• [x] I have tested my changes and corrected any errors found

[Casperento]

Everything tested and working as expected

[Casperento]

Sounds good. About the civilian classes, i'm not sure yet how can we work it. I'm opened to suggestions..