Added in basic spike display in TraceView
Spike visualisation on TraceView (not working)
Removed TraceView spike line display due to tricky Galry bug
More Pythonic spike visualisation implementation on TraceVeiw
Faster implementation of TraceView spikes in a separate thread
Toggle with S for spike visualisation on TraceView
Decreased undersampling to get round invisibility at high zoom bug
TraceView now highlights spikes only on masked channels
TraceView now highlights spikes with correct cluster colours
TraceView spike-highlighting trace colour is now less bright for better contrast
TraceView now sets unlighlighted colour in traceview.py rather than kwiklib
5x speedup when generating spike highlight colourmap in TraceView due to use of np.searchsorted()
1000-10000x speedup of spike highlighting by using bisect rather than np.searchsorted()
Always generate spike highlighted trace in TraceView for much faster toggling
Faster TraceView spike cluster colouring
No longer reopen saved TraceView on restart

This is a workaround for a couple of bugs - one where TraceView
windows can be hidden and somehow not show (but still consume RAM
and CPU), and also another where files must be opened before
TraceView, partly as another workaround for some Galry issues.
TraceView doesn't return an error when no .raw.kwd
Merge pull request #40 from klusta-team/kwikskope_spikes

KwikSkope spike display