FEATURE: added core regex module

[elias-michaias]

Contains a bunch of tests inside of the main function as of now

[elias-michaias]

I followed your instructions in changing method names, but there is currently a compile error because str.alloc_copy doesn't exist as a counterpart to string.alloc_copy. You will have to fix that before this compiles

[elias-michaias]

Fixed instances of str.alloc_copy to just str.copy.

[elias-michaias]

Hold off on merging; need to add some functionality and do some refactoring