GraphViewer now displays the fraction of channels within each node that are set to record. Closes #135

Previously, every event would be saved multiple times if
it passed through multiple processors. Now,
GenericProcessor::getNumSamples() checks for existing TTL
events and changes the processor ID (byte 2) to zero.
If the RecordNode encounters an event without a positive
processor ID, it will ignore it.

The only potentially dangerous thing about this is that it
involves modifying the MidiBuffer. But as long as the size
of the buffer doesn't change (just the value of certain
bytes), this should be fine.

The RecordNode was accidentally starting the timestamp at the
beginning of the event buffer, rather than at byte #4.

Allows parameters to be set from saved XML and changes the
parameterEditor buttons (currently for discrete parameters only) to
reflect which parameters are currently used by selected and
non-selected channels. This fixes a problem where the buttons would
always show what the last press was rather than the current values for
the active channels (e.g. If you changed the parameters on Channel 2,
and then switched to select only Channel 1, the GUI would incorrectly
indicate that the settings for Channel 2 were active). Additionally,
allows the user to see what parameter values are used for channels not
currently selected.

- Clean up methods in GenericProcessor
- File selection now happens outside of EditorViewport
- Add mechanism for saving custom parameters for individual channels
- Settings file is automatically saved at the start of recording

To run this in the future, install astyle (sudo apt-get install astyle),
then enter the following from the top-level project directory:

astyle --options=astyle.options --recursive "./Source/*.cpp" "./Source/*.h"

This will convert tabs to 4 spaces and ensure that brackets are on
their own lines.

Use the following command to update the copyright year in all files,
starting in the Source/ directory:

find . -type f -print0 | xargs -0
   sed -i 's/Copyright (C) 2012/Copyright (C) 2013/g'

Works like a charm!

getInputChannelName() and getOutputChannelName() (pure virtual in the
superclass) aren't returning anything. So far this hasn't triggered
any memory errors because nobody's calling them.

To hack around this, have both of these return
"xxx-UNUSED-OPEN-EPHYS-xxx" (none of the existing subclases override
these methods, so leaving them pure virtual isn't workable). This way,
if we ever start calling these, we'll notice right away that a fix is
needed (instead of segfaulting, etc.).

Also keep them virtual to allow overrides.

Signed-off-by: Marti Bolivar <mbolivar@leaflabs.com>

That's not gonna work. Since nullParam is just a "nothing found", put
it in static storage and return that.

Signed-off-by: Marti Bolivar <mbolivar@leaflabs.com>

Generic changes:

- Genuinely unused variables (-Wunused-variable): delete
  them. Sometimes add a comment if the variable is for an extension of
  the code that isn't done yet.

- Variables that became unused due to commented-out
  code (-Wunused-variable): comment out their definitions. Dirty, but
  that's because commenting out code instead of deleting it is
  dirty.

  Many of these are due to commented-out printlines that should have
  been log messages that only get emitted at high verbosity level.

Specific changes:

- SpikeObject.cpp (-Wunused-value): move initialization of loop
  variable into first for loop clause to silence the warning.

Signed-off-by: Marti Bolivar <mbolivar@leaflabs.com>

Rearrange member initialization in constructors to silence GCC
-Wreorder warnings (-Wreorder is enabled by -Wall).

Signed-off-by: Marti Bolivar <mbolivar@leaflabs.com>

Uses the parameters array to create XML data for parameter settings on
each channel when saving.

This only works for processors that use the parameters array, though I
updated LFP and Signal Generator to update that in parallel (LFP seems
to have an unrelated bug in dealing with channels that is causing some
problems). Eventually, all parameters should be used in the parameters
array, since it opens up a lot of possible holes when using default
values (they need to be specified twice), and once loading is
implemented. I've fixed some of the problems with parameters, so this
should be easier to do.

As part of this, I also fixed the implementation of
addParameterEditors. The old way of implementing a custom parameter
editor was to rewrite the virtual function, but because it was called
in the constructor, this didn't work (constructors use the type of the
parent). Instead, all editors now also pass a bool
"useDefaultParameterEditors" which is used by addParameterEditors() to
determine whether to do anything. I think this is the best way to do
it. It's initialized to default as true, though I had some trouble with
it implicitly taking the argument and so had to add true to most of the
editor functions (which is probably good practice anyway).

I also fixed some of the functions for generic processor to get
parameter index and parameter name.

Obviously, this is of considerable less use without functions for
loading parameters, but I figured it'd be better to make available for
testing with just the loading in case the changes to Parameters broke
anything I missed.