Channel selection now takes place within a slick new interface. It's not
yet tied to actually changing parameters, but things should be much simpler
code-wise, as well as visually.

UIComponent, ProcessorGraph, etc. were still referencing the configuration
class (but not using it). Those references have now been removed, as the
configuration object will be replaced by a set of parameter and channel
objects.

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

If continuous channels are toggled for recording within their respective editors,
a "writeContinuousBuffer" function will be activated within the RecordNode. This
function doesn't do anything yet, but it will make it easy to add diskwriting
capabilities in the near future. Once a stable format for events has been established,
a similar function will be implemented for writing event buffers to disk.

the SpikeDisplayCanvas now supports scrolling! i had to change OpenGLCanvas::showScrollBars() from private to protected. Additionally I made scroll pix protected although that might not be needed.

A preliminary version of the ProjectionAxes that renders projection points using a texture instead of drawing each point. This should allow the plots to translate around the page without problem.  Additionally the plot can be flagged to regenerate the texture from scratch using a circular buffer of accumulated amplitudes. This hasn't been tested yet.  Additionally this code is very alpha and needs to be cleaned up and could break at any time.

Started integrating the TetrodePlot class. Oddly the projection plots aren't working although they were working in the stereotrode class, I'll have to figure that one out

Problem:
- There's not yet a way to get the parameters for each channel
after it's clicked

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.

But they won't do anything useful until the ProcessorGraph is updated

The EditorViewport now contains buttons to scroll through multiple tabs,
or scroll across long signal chains. Now, there can be infinitely
many signal chains of infinite length (if you have a lot of time
on your hands).

Functions for managing the signal chain are no longer handled by
the EditorViewport, but by the SignalChainManager

Three important changes:
- The FilterList is now the ProcessorList
- The FilterViewport is now the EditorViewport
- Any classes that need to access important UI objects have become subclasses
  of the "AccessClass". Such objects automatically obtain pointers from
  the UIComponent and register the MessageCenter as an ActionListener. This
  will make it much easier to allocate pointers to objects.

Previously, if you placed a sink in front of a source, it would lead to
a never-ending "while" loop. By removing two lines (254-255), this problem
was solved.

In combination with an EventNode, a WiFiOutput node is able to send a
simple message to a hard-coded address via UDP. This is the first sink that
actually emits an output. It's obviously over-simplified, but as a
proof-of-concept, it seems to be working well.

The IntanThread was occasionally looking for data after acquisition was disabled,
which would trigger the SourceNode to attempt to manually disable callbacks.
The only negative effect of this was that if the user was currently viewing
a different signal chain, it would switch back to the Intan chain unexpectedly.
This is no longer the case, as the SourceNode checks to see whether or not
it received a proper disable signal from the ProcessorGraph before notifying
the UI that data may have been dropped.

Generic Editors colors now match the type of processor.
The FilterViewport layout has been changed to a simple outline.