Make usable for normal people

[olejodd10]

The goal is that this will be a program people will keep a shortcut to on their desktop. Need this:

• Icons for task bar and in the upper left corner of window (esthetics only)
• A better way to provide midi path (preferably "open file"-dialog)
• Make sure image paths are correct when running the final executable

[olejodd10]

Also rename from stemmefil to midi something