ltihooks.py apparently breaks the import mechanisms of Python 2.6,
causes SWIG's runtime to fail to share a global type table, and
yields various failures in our tests.
* wrap/python/ltihooks.py: Delete.
* wrap/python/Makefile.am (EXTRA_DIST): remove ltihooks.py.
* wrap/python/tests/bddnqueen.py, wrap/python/tests/interdep.py,
wrap/python/tests/ltl2tgba.py, wrap/python/tests/ltlparse.py,
wrap/python/tests/ltlsimple.py, wrap/python/tests/minato.py,
wrap/python/tests/modgray.py, wrap/python/tests/optionmap.py,
wrap/python/tests/setxor.py: Do not use ltihooks.
* wrap/python/tests/run.in (pypath): Include the .libs/ directory
in the search path so that Python can find the *.so libraries.
