Refactor Utils (mostly) out of global namespace

This commit reframes the Utils module to be more self-contained, and now only
the Number prototype methods and the every/after/constantly methods are exposed
globally.

I'm unsure about whether these methods can be more scoped such that people can
turn them off if they want, but that's potentially something to look into in the
future.

This commit also updates most of the other source files in Cylon, requiring the
Utils module rather than assuming the methods are in the global namespace.

A similar batch of commits will need to be made for all other Cylon modules to
make sure they don't explode when they can't find #subclass or something like
that.

To make the previously-global methods available, both in submodules and for
people looking for them, all the utility functions are exported in Cylon.Utils.