python/generate-python-exceptions,
python3/generate-python-exceptions: Remove comment which is no
longer correct since #538 was fixed 4.5 years ago.
python3/python.i: Don't release the GIL when using
XapianSWIGQueryItor as it uses Python C API calls.  (fixes #346)
python3/pythontest.py: Actually reenable the test case which was
failing before the previous commit fixed the underlying problem.
python/python.i: Don't release the GIL when using
XapianSWIGQueryItor as it uses Python C API calls.
Merge remote-tracking branch 'upstream/master' into pkgconfig