Clean commit of 16-bit monochrome JPEK2000 support
Merge the rest of the patches

Now it actually works and passes the test suite
Add tests and fix a 16bit vs 32bit integer bug

Yay unit tests!
Merge pull request #730 from videan42/jpeg2k-16bit-clean

16-bit monochrome support for JPEG2000
Update CHANGES.rst [ci skip]
No longer use Tests/run.py
Fix manifest