Fix problem with directories #10
Description
Currently, the directory structure is a problem. Sample libraries often habe a base directory and a single sample directory. DrumGizmo standard kits have a base directory and then within a directory for each instrument containing the instrument xml file as well as the sample directory for this instrument.
As DGPatchMaker was designed for sample libraries, the first model was implemented. This is not so nice for editing standard DrumGizmo kits as on export the structure will be messed up.
Thinking about this and implementing a solution which can handle both situations in the most efficient way.