another baby step - namespace adjustments

[DJ Delorie]

> Don't you think it would be simpler to put the damn function in
> libiberty and be done with it?

Well, yeah.  But if doing it the "right" way is just as easy, we can
avoid potential headaches in the future (we've been fiddling with math
routines for a long time in djgpp-land, trying to get all the edge
conditions right).  Forcing our own sqrt makes libiberty bad for apps
which need exactly the right floating point behavior - it's unlike
integer ops which we can emulate exactly.

But we're quickly running out of easy options...