Obsolete building in source dir?

[DJ Delorie]

> Could someone remind me what was wrong with the "if configure
> notices it's been invoked in the source directory, create a build
> directory behind the user's back" idea?  That wouldn't break all the
> time.

It's the "behind the user's back" that's a problem.  I think that we
should either make it do what the user expected, or tell the user they
can't do that, but to do something the user doesn't expect is bad.

Plus, the toplevel stuff is shared among many projects, and only gcc
has a problem with building in srcdir.