removing src/dejagnu, src/expect

[Ben Elliston]

At yesterday's GCC Summit testing BOF, there was a strong concensus
that these directories should be removed from the src tree and that
developers should install the latest releases of Expect and Dejagnu
from their distribution/packaging system or from a source tarball at
ftp.gnu.org.

I'm declaring that I intend to do this and no sooner than Friday June
11 at 00:00 UTC.  I will be ensuring that no local patches, if any,
are lost in this process.  If you have any reasonable objection,
please say so now .. :-)

Cheers, Ben