Select lib directory matching current python version if there is more than one present
Handle the possibility of other tests failing in Python code called from C
Avoid treating exception as a tuple as this no longer works in python 3
Apparently "del m.handles" does not work in python 3
Add a test for general object behavior as it seems to be changed by python 3 patch
Check multi and share objects for attribute assignment behavior
Test overwriting pycurl constants in pycurl objects
Fix curl multi constants not existing on curl multi objects.

curlmultiobject_constants was never set to a dictionary but remained NULL.
Therefore insint_m never populated it. As a result, multi object instances
never had any of the constants they were supposed to have.
Make it possible to run test app without pycurl being installed
Merge pull request #67 from p-push/python-3-compat

Python 3 compatibility changes