Added Functions Library. Closes #44.
Added fn_getFromPairs.sqf to functions library, its a copy of BIS_fnc_getFromPairs with a workaround for not being able to return "nil", see http://feedback.arma3.com/view.php?id=20643
Changed all calls to BIS_fnc_getFromPairs to use cTab_fnc_getFromPairs instead.
Improved cTab_fnc_settings to only call cTab_fnc_IfUpdate with values that have changed.