TraceView improvements

[nippoo]

A few things to consider and prioritize:

• [x] Jump to next spike in selected cluster(s) with Ctrl+arrow
• [ ] Show filtered data (realtime filtering with same parameters as spike detection)
• [ ] Jump to next simultaneous occurrence of spikes / all selected clusters with Ctrl+Shift+Arrow (hopefully this will be fast enough!) - within viewport aka 500ms etc
• [ ] Move backwards/forwards with mouse continuously rather than discrete jumps
• [x] Show all spikes (not just selected clusters) by pressing S
• [ ] If selection of spikes in WaveformView is possible, jump to that spike when it's selected
• [ ] Zoom out arbitrarily to see LFP - 10 seconds? 100 seconds?
• [x] Only show unmasked channels for cluster(s) which are selected. With 300 channels it's carnage

[rossant]

• +1 to all
• except "Move backwards/forwards with mouse continuously rather than discrete jumps": the benefits/cost ratio is far too low IMO
• I'd add "mode with static undersampling and no spikes to allow showing really long intervals"

[rossant]

things to add:

• extra traces
• event trains (vertical lines)