winsup testsuite

[DJ Delorie]

I've just added a primitive testing framework to the winsup directory,
which should show up in tonight's snapshots.  The idea is to be at
least minimally compatible with dejagnu standards, support
cygwin-specific tests, and run on a cygwin host.  Currently, there are
no tests in the testsuite (except for a few samples).  Use "make
check" to run it.  There is a winsup/testsuite/README file.