Split a spiketimes object with multiple repeats into list with one entry per repeat

Deprecated as of gphys 0.9 and will be removed from gphys 1.0 (CRAN release).

# S3 method for spiketimes
split(x, f, drop, ...)

Arguments

x	The spiketimes object
f	number of waves per block - deduced from odour names if missing
drop	IGNORED
...	IGNORED

new spiketimes object (list) with one entry for each block of odours

Only works for spiketimes from single pxp file. FIXME Teach this to cope with repeat blocks with different odours in different order