Utils for alloy

[GarrettBurroughs]

In alloy, there is going to be an included Utils class that contains common rather simple self-contained algorithms to aid in writing code. For example, a constrain method. What other methods should be added?

[GarrettBurroughs]

A few math functions have been implemented on the latest version, including a sign function that returns the sign of a value (-1 if negative, +1 if positive). Aswell as a second power function that preserves the sign. Eg. pow2(-5, 2) = -25.