Replaced references to external drive scl_sggf with new drive label SPARROWHAWK
Replaced references to external drive SCL_SGBUP with new drive label PLETHRON
Made removing empty trials from vals default (again), comments added
Added comment
Seperated getting the quick threshold curve into a seperate function
Large changes. Added quick threshold curve method of initial estimate. Made loop work with two initial estimates in place. Added linear interpolation as secondary model of fitting. Made firing rate accurate (in Hz). Seperated NSE firing rate measurement out into its own function.