Hydrogen (Advanced drum machine for GNU/Linux)

This patch release fixes a bug introduced in 1.2.5 and other minor issues. Added - The AppImage version does now provide all drumkits in /usr/share/hydrogen/data/drumkits/ and /usr/local/share/hydrogen/data/drumkits/ via the "Sound Library" as session kits. Changed - Sample loading in songs has been made more portable. Fixed - Fix velocity automation for patterns that are not of size 4/4 (#2171). - Fix saving and loading of sample files introduced in 1.2.5 (#2174).