Through the SpikeDetector Editor, it's now possible to change the channel
mapping for each electrode and adjust thresholds. It's not yet possible
to inactivate particular electrodes or change parameters over multiple
electrodes at once; these will both be necessary functions in the future.

Now, when the user clicks on a tab in the DataViewport, the corresponding Editor becomes
active. Likewise, when the user selects an Editor with a Visualizer, the corresponding
tab becomes active in the DataViewport.

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.

Added method for creating parameter editors, which can be overridden by subclasses of the GenericEditor

I commented out the activateAntiAliasing call and added a call to disableAntiAliasing for the SpikeDisplayCanvas as antialiasing messes up the projection plots. We can revert this change in the future if we come up with a way to enable anti-aliasing without completely messing up the projection plots

Slightly altered the layout of the SpikeDisplayEditor, also I changed the waveform line width from 1 to 2 pixels