Fix Channel.Color interpretation in ImageJ

This prevents the color from being interpreted as ARGB instead of RGBA.
Add support for PCORAW data

Fixes ticket #11503.
Change comment delimiter to make retrieving/testing the comment easier
Fake: allow channel color to be specified

The 'color' attribute allows the color to be specified as an RGBA
integer, in either base 10 or 16.
Clean up image description population
Fake: minor fixes to channel color parsing/population
Revert "travis: Build with OpenJDK8"

This reverts commit 40f7f18e7b246c28c7539e678bebc8fcdc0064dc.
Merge pull request #805 from sbesson/travis_fix

Revert "travis: Build with OpenJDK8"
Merge pull request #791 from melissalinkert/pcoraw

Add support for PCORAW data
Merge pull request #767 from melissalinkert/imagej-color

Fix Channel.Color interpretation in ImageJ