Updated hydrogen to 0.9.7.

2016-11-01 the hydrogen team <hydrogen-devel@lists.sourceforge.net>
* Release 0.9.7
* The color of the SongEditors squares is now configurable
* Added support for midi cymbal choking
* Added support for midi hihat pressure control
* Added hihat pressure groups
* Added basic non session manager support
* Added instrument components
* Basic lilypond export
* New windows cross compilation script
* Support for soundlibrary images
* Configurable sample selection algorithm
* Support for soundlibraries with images
* Donation dialog
* New midi action:
* SELECT_PREV_PATTERN_RELATIVE

(wiz)