added instructions to run examples in readme
removed load_path business from parallel sort
ran reformat on parallel sort
replaced while loop with untill with || instead of 'or'

using 'not', 'and', 'or' is dangerous because of an odd operator ordering thing. We should always use || && !
using += instead of .concat
gave variables simpler names
removed funny threshold business

It made everything more confusing
renamed merge_sort to merge

it's not sorting technically speaking
fixed a potential memory leak.

Since a thread has a task, the task references the thread which references a task. This is a classic recipe for a memory leak. It may not be a memory leak as ruby might be smart enough to realize there's a loop in the references, but you're never sure.
removed the not_parallel sort

The goal of these examples is to show how the blocks work not to time
 the code. Also, we're going to lose no matter what. The ruby GIL
 will make this whole thing moot.
added a note on GIL to the readme
bumped version to 1.0.1