clang-3.9 is now available with apt add-on in travis-ci

This ensures all openjpeg.h dependencies are met.
Fix #673

allow user to store either capture or display resolution, either from command line, or read in from image. Currently, image resolution is only supported for TIF input images.

This reverts commit 1d982555afb337345be573b5e67e7605dc6a11c9.

Update to mm2/Little-CMS@e342f44

This reverts commit e5f53a4355a19e8106439ffb1610c0bd0c044e59.

Avoid lock-up on low-memory systems