This function takes three numbers,
the first is a number that is to be wrapped to a value
between valueA and valueB inclusive.
The value returned is a value
that is 'wrapped' between the two other values e.g.
Wrap(0,0,10) returns 0
Wrap(-1,0,10) returns 10
Wrap(-2,0,10) returns 9
Wrap(11,0,10) returns 0