Modified the pngs for the 5th radio button to have a non-edge style.  Additionally I added a 6th button for generating spikes that has a spike waveform.  I don't have the Jucer running locally so I can't add these files to the BinaryData class.

The waveform icons should be made a bit thicker, but otherwise these look cool.

The control panel now holds an "AudioEditor" to adjust volume
and open a window to alter device settings. Audio output is definitely
working, but different buffer sizes make it sound really weird. The
same problem is present in the Juce demo app, however, so I don't
think it's a problem inherent in the GUI.

The FilterList is now an OpenGLCanvas. It now uses custom fonts (which have
been placed in the Resources/Fonts/ directory), and a completely customized
design. Nevertheless, it seems to retain the same functionality as the old
TreeView-based FilterList.

Minimizing the FilterList is now possible, which allows the DataViewport
to extend the entire length of the window.