added settings load/save facilities

added some code comments

fixed threading issue with tasks

added audio export code
	needed to introduce a blocking rendering within generator
	as all threading attempts failed :/

changed soundsink interface
	additional interface for hardware sinks

added scroll-bar functions to ensure a given coordinate is visible
	slider should now always be visible

fixed some:
	uninitialized values
	wrong setup order
	memory leaks for midi events (switched to unique_ptr)

fixes/changes to timeline:
	fixed wrong caching (missing static, wrong types, ..)
	changed zoom (new base for calculation)

fixed workspace loading with empty track descriptions

some minor improvements to drawing / editing notes
	still a lot of work to do here :/

fixed many warnings and wrong project file-setup when compiling with llvm/clang

hopefully fixed gui threading issue with the slider..
	was updated from a non-gui-thread