add plyr as package dependency
ignore more emacs files

#*# are backup or temp files from emacs.
Use [#] in pattern so # is not taken as a comment.
This would be fine for master too.
more tweaks to plyr code

I PROBABLY SHOULD NOT USE PLYR.  It's ordering of the rows differs from
that used by the rest of the system, e.g., via split.data.frame and
subsequent lookup based on imposed labels (e.g., 2l.norm.r).
In either case handling of out of natural order ids, or disjoint ids (a
single id appears in non-contiguous rows) is a potential problem area.
I think the master code's handling of it works.
All my invocations of plyr are wrong, except this corrected one.
Important points are
1) You must refer to the id symbolically and can't just use a variable
known i the call.  So .(id) is good as the level argument, but fg.full
is not.
2) One data frame inputs have the splitting semantics I need.  Arrays
are only split by dimension
3) Regular functions don't work as the .function argument.  Instead use
helpers like count here or, more typically, summarize.