TODOs for D-1 :S :S :S
Open questions on the multivariable normal's code
Found a time-sink; marked it with a TODO
Merge branch 'master' of https://github.com/Daniel306/stat440
Make speed tests easier to debug
Commit some debugging
Merge branch 'master' of https://github.com/Daniel306/stat440

Conflicts:
	R/test.constants.R
	R/test.speed.R
	R/test.speed.main.R
cumvar(), which computes cumulative variances (of vectors only!!)
test rearchitecture to support analytic moment formulas
[UNTESTED] import the marginal variance formulas
hacks to speed up test.correctness.R dev cycle
omg i broke everything in the (second) last commit
start to rewrite the moment code: cummean.marginals and cumvar.marginals
yakshaving: marginals_do, which has the magic (which turned out to be do.call) I was looking for years ago.
yakshaving: idx2title
yakshaving: reasonable_subset
[BROKEN] large refactor to expressing convergence plots much more elegant

Someone on #R helped me figure out how to do S[*idx], which was the breakthrough
that allowed me to trim and shorten a lot.
Also I decided to toss out trying to be speed-efficient in favour of being expressivity-efficient:
 good bye cumvar and cummean (((they're still around, but I'm not using them)))
This is all in support of making expressing analytic
[BROKEN] cleanups that get the code closer to running again
[STILL BROKEN] repair ..getitem.. (it actually never worked)

R uses symbols (a la lisp) for its funky slicing tricks. I don't know how to make symbols,
 so I use inventedthe convention that NA means "ignored"
[SORTA FIXED] plot.densities now works as it used to again.

I am very happy with where this is going. I just hope I can finish it in time to write the report.