new build scheme naming

[DJ Delorie]

> That actually *works*?  It doesn't fail because the million Make
> variables passed down from the top level are missing?...

Yup, I do that all the time.  For normal builds, the variables passed
down happen to be the defaults anyway, so it doesn't matter.  But for
some things (like, say, building target libraries) it's more important
to be called from the top so that you get the variables.  GCC's make
just happens to work without them, that's all.

> Why are we passing all these variables down to lower level makes?

In case you need to override them on an all-build basis.