Use Alpine openjpeg package

[SaschaAdler]

Newer openjdk images are based on Alpine 3.8, which has openjpeg v2.3.0 in its package manager. I suspect we can revert to using the package instead of building openjpeg from source.

[RussellMcOrmond]

http://online.havarti.canadiana.ca/view/oocihm.99400/1 is the image referenced in cantaloupe-project/cantaloupe#111 . I pointed Havarti at Brie/Caboc which is using the latest build of the v4 branch.

[SaschaAdler]

I've tested the above commit on the further above image. Russell, I'll let you test things out elsewhere if you like.

[RussellMcOrmond]

I built the image, and got "Cannot run program "opj_decompress": error=2, No such file or directory".

I've changed the Dockerfile to install the openjpeg-tools which brings in the command-line tool called.

[RussellMcOrmond]

Tagged as docker.c7a.ca/cihm-cantaloupe:4.0.2 and deployed to server used in production.