warning about classpath import

[Tom Tromey <tromey at redhat dot com>]

I'm finally ready to do another classpath import, and near the last
minute I realized that the import may temporarily break the build, due
to an unfortunate interaction between the classpath Makefile and the
way cvs import works.  FWIW I'd prefer to continue using cvs import
since it does seem to help the process a little.

So, I thought I would put off the import for a little while and warn
people about it.  Unless there are objections I am going to do the
import on Friday.  I've already done all the needed testing so the
window of breakage (should any occur) will be reasonably small --
enough time to import, update, and then apply a few required patches
to libgcj.

Tom