Upgrade channel selection interface

This page contains more details about the project idea.

Description: Every processing module within the Open Ephys GUI includes a generic interface that allows the user to select subsets of channels for editing parameters and toggling recording on and off. Currently, users can only select or deselect one channel at a time, and the interface does not scale well to high channel counts. We're looking for someone to re-design the interface so that the buttons for each channel can be visualized more effectively and channel selection can be performed more efficiently.

There are a few somewhat related aspects to this:

Update channel selection:
Make it easier to select channels - this could be a fairly simple upgrade to the existing UI but with better selection of channel ranges, better handling of high channel counts etc.
This should be in the form of a generic channel selection UI that can be used anywhere. Maybe a text box that can handle inputs like "1-13, 16" would be useful for instance.

Add UI for routing groups of, or individual channels:
Currently, the UI allows for remapping channels and splitting the output of a processor into two streams, but there is no explicit representation of what channels are passed between processors, and splitting off individual channels from one processor into a separate stream or combining streams is currently very tricky.

Improvements could start at simple small visual indicators of how many channels are passed between processors, to UI improvements like allowing users to spawn splitters by clicking on the space between processors, improving the splitter functionality to allow splitting into subgroups of channels etc.
We could also think about UI more along the lines of http://www.neuromore.com/neuromore-studio/ or https://bitbucket.org/horizongir/bonsai/wiki/Home 

Update file saving UI:
Somewhat relatedly, the selection of saved vs unsaved channels should be updated, so that eahc processor makes clear whether data is saved or not. 
See feature request https://github.com/open-ephys/GUI/issues/197