Incorporate data compression

[JoeZiminski]

This will fall into two parts

1. use compressed format for all intermediate data (potential problem with this is that some intermediate data e.g. written for kilo sort cannot be compressed as KS cannot read it. So actually, this doesn't really world. It is better to instead delete it outright. But other intermediary steps can probably be compressed e.g. waveforms
2. Compression of input data. spike wrap could automatically compress input data. This is the best approach for compressing as much data as possible but will have to be a user-set switch