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.