Test for ClassicQuicksort. InsertionSort functionality

ClassicQuicksort now has tests. The tests aren't thorough
but they're sufficient for now (I'm probably jynxing it).
ClassicQuicksort now also does insertion sort if a threshold
is met and there's a flag indicating the InsertionSort should
be done.

The InsertionSort functionality is tested.
Updated .gitignore for LaTeX files