Remove aplib dependencies from coro

Enhanced the print_profile module to support comparing two profiler results. The comparison only works one-way (not a diff). The first input is considered as the baseline and the functions in it are compared with the second one. So this is intended to be run as "print_profile <new_result> <old_result>" to see what changed in new_result to make it slower (or faster).

Require cython + pyrex to allow Shrapnel to be install via pip

Require cython + pyrex to allow Shrapnel to be install via pip (http://mail.python.org/pipermail/distutils-sig/2007-September/008204.html)

on aplib.

define __swap() with and without extra underscores to cover osx/mach