Converter bugfix and save dialog

This release fixes a bad bug in the pitch conversion in the converter script (it was basically broken for all non-octave pitches for Cinter 4 samples).

It also adds a directory dialog that pops up whenever a sample is saved. Thus there should be no more confusion about where the sample file ends up.

Stand-alone VST plugin

The synth is now available as a stand-alone VST plugin, removing the dependency on MetaSynth.

Builds of the VST are available for Windows, Mac and Linux.