First check in
Support for delta-format in input file

Modified the loadEpisodes method in main so that it can load a file
where the episodes are in a delta format wherein each episode (besides
the first) is specified in terms of which WMEs add/remove from the
previous episode.  See log_eaters_changesonly2.txt for an example of
this format.
Merge branch 'master' of https://github.com/amnuxoll/EpMemHashing.git
Added stub class for GAHashFn