the various profiling modules (profile, cProfile). Patch by Hagen Fürstenau.

Perform additional cleanup, mostly deleting from sys.modules, or clearing the warnings registry.

* Convert both to unittest.
* Use the same unit testing code.
* Include the expected output in both test files.
* Make it possible to regenerate the expected output by running
  the file as a script with an '-r' argument.

Based on lsprof (patch #1212837) by Brett Rosen and Ted Czotter.
With further editing by Michael Hudson and myself.
History in svn repo: http://codespeak.net/svn/user/arigo/hack/misc/lsprof

* Module/_lsprof.c is the internal C module, Lib/cProfile.py a wrapper.
* pstats.py updated to display cProfile's caller/callee timings if available.
* setup.py and NEWS updated.
* documentation updates in the profiler section:
   - explain the differences between the three profilers that we have now
   - profile and cProfile can use a unified documentation, like (c)Pickle
   - mention that hotshot is "for specialized usage" now
   - removed references to the "old profiler" that no longer exists
* test updates:
   - extended test_profile to cover delicate cases like recursion
   - added tests for the caller/callee displays
   - added test_cProfile, performing the same tests for cProfile
* TO-DO:
   - cProfile gives a nicer name to built-in, particularly built-in methods,
     which could be backported to profile.
   - not tested on Windows recently!

causing the profiler to crash on an AssertionError if the same Python
function catches multiple exceptions from C functions.