Weird behavior was observed during fwrite when files were only opened
with "a". fwrite did not write the expected number of bytes (probably
augumented things with a \n or \r). This caused serious problems parsing
the dumped files in matlab. Forcing a binary fopen option fixed things.

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

Whenever files are needed for recording, the RecordNode opens them. When
they are no longer necessary (either recording has stopped, or recording
of a particular channel has stopped), the RecordNode closes them.

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.

Since every processor now gets asked to enable() prior to the start of
acquisition, it's much simpler to move the steps involved in preparing
for acquisition into these methods. This the processor from beginning
acquisition when prepareToPlay() is called upon initialization.