Unit tests of internal functions

[Sam Hartman]

I'm still coming up to speed on this.  My initial reaction to building
static libraries is fairly negative.

I think my preffered option may well be to deal with the build
aggrivations of the current approach and to fallback on options 1 and 2
when that proves too problematic.

Option 3 seems reasonable in terms of result, but I'm not convinced the
build system complexity is justified.

If my input is going to be seriously considered it's a good idea to
sanity check that  the build system complexity of our current practice
isn't more than that of option 3.