colormatrices: nikon d600 enhanced matrix

thanks to Michael Below
updated about dialog to reflect contributors 1.4..1.6
release notes: update somewhat.
release: remove <95% translations. put back after release.
about: remove (partly outdated) special roles.
release notes: empty after release
Revert "release: remove <95% translations. put back after release."

This reverts commit fe7c121054c35e40091f95f9e7e606e25753c979.
Exposure IOP: deflicker is back and kicking

This reverts 461777143735bcb8698bb8487cf6a1dcd71986fa, 148e0f90172c6650e40b2ace1ce918b7b5317458
Cleanup the NX3000 decoding code from dcraw
OSX packaging: once again try to make osascript call reliable
OSX: make afplay default audio player (no aplay here)
Re-enable flags in image info lib
Gentoo packaging: switch from libgnome-keyring to libsecret
get rid of DT_PIXEL_APPLY_PPI to avoid confusion
darkroom: scale processed view with window size
Switch to GTK3 in cmake
Import osm-gps-map-1.0.2

Previous versions does not compile with GTK3
Cleanup CMake system now that GTK uses pkg-config
Respect REQUIRED when looking for GTK3 components
Load darktable.css instead of dakrtable.gtkrc

This is just a sample .css file with a dark background color to see if
loading worked.