Goose Update

[Jon Trowbridge <trow emccta com>]

Except for my use of erf() and erfc() at one point, and a few NANs and
isnan()s that are still floating around in there, I've pretty much
gotten goose to the point where the library will compile without any
warnings while -ansi, -pedantic and -Wall are all set.  This is
necessary since we need maximum portability to make sure that goose
compiles properly under <*gasp*> Windows.

Also, I actually wrote a tiny bit of primitive, fragmentary
documentation.  I don't know what came over me...

Another milestone: Goose now actually has some non-trivial statistical
functionality!  The LinearRegression class now knows how to handle
inference concerning the model parameters it spits out, and can do a
t-test against the null hypothesis of independence.

Coming soon, regression diagnostics --- leverage, DFFITS, DFBETAS,
Cook's D, studentized residuals... If SAS or SPSS can do it, we'll do
it better.

-JT