this merge contains:
* a new plugin architecture
* a pluginized pytest core
* many pytest related refactorings
* refactorings/streamlining of pytest's own tests
--HG--
branch : trunk
KeyboardInterrupt handling:
* in --verbose mode, print a detailed traceback at the end of
the report.
* in non-verbose mode, only print the file name and line number
where the KeyboardInterrupt occurred. That's the minimal
amount of information that is of any help at all to locate
an infinite loop somewhere.
--HG--
branch : trunk
* moving in test, misc, code, io directories and
py/__init__.py
* py/bin/_find.py does not print to stderr anymore
* a few fixes to conftest files in other dirs
some more fixes and adjustments pending
--HG--
branch : trunk
