Add GraphViewer class to interact with EditorViewport
GraphViewer now reflects the structure of the ProcessorGraph

Splitters are supported, but Mergers are not. Still a bit buggy,
but it's definitely a start!
Update GraphViewer rendering
Minor updates to GraphViewer code
Update GraphViewer code
Adds save and load of config capabilities to serial input.
Merge pull request #114 from FloFra/serial

Adds saving and loading of configuration capabilities to serial input.
Merge from FloFra repo
Merge branch 'master' of https://github.com/open-ephys/GUI
Merge GraphViewer code from spikesorting branch
Make SerialInput buffer a constant size
Add collapsible editors and fix GraphViewer issue
Merge branch 'master' of https://github.com/open-ephys/GUI
Update ChannelMappingNode from spikesorting version
Fix issues with loading SpikeDetector parameters
Clean up SpikeDetector parameter loading
Prevent channel overflow by setting firstChan to 0
Change version number to 0.2.3
Visual Studio updates
Update FilterNode from SpikeSorting branch