trivial: Fix a small memory leak when using cd_icc_utils_get_coverage()
trivial: Fix up a small and large memory leak in the self test program
trivial: Fix a tiny memory leak when writing MLUC tags
Use the new cmsContext functionality in LCMS 2.6
libcolord: Fix the GObject introspection for cd_device_get_profiles()

This allows us to use the method in python.