BUG: Don't wrap vtkProp.Get/SetAllocatedRenderTime

This method isn't really a public method that should be wrapped and has
a non-standard Set method.
Fix test_generic_module.py.
Prettify test_flow.

Made the flow a little more interesting, the code was also raising a
divide by zero warning which has been removed.
Fix test_streamline errors.

Adding new test images.
Merge pull request #105 from prabhuramachandran/fix_integration_tests

Fix integration tests