refactoring within the backend (split into several files)
modified getters/setters for midi events

added slight smoothing to waveforms in order to avoid aliasing effects.
there is still a lot of work to do here i guess.. many things to learn..

note: LUTs should be created once only! not per oscillator! / on every mode switch

fixed including issue for wave-sink
changed oscillator LUTs and moved them into a singleton to reduce
CPU-time and memory: LUTs are created only once and on-demand
additional helper function to load QIcons from skin files
added all header files of KSynth to the GUI project
(is there some way of using wildcards for sub-directories??)
started working on CRUD for note events.. still many things todo
but some aspects already work as they should ;)
as the model for midi events has changed (pointers-to-struct instead of structs)
some parts of the backend and GUI needed a change
some GUI changes for a better look. i think i need someone providing a
reasonable design :P