Delete the pass (one of twelve) that does all KDC exchanges with TCP;

Delete the pass (one of twelve) that does all KDC exchanges with TCP;
add a test case that sets that up and runs kinit.

Add a new support proc that allows running a test only once despite
multiple passes; use it for the tcp and iprop tests.

According to one totally unscientific measurement, this reduces the
tests/dejagnu tests run from ~4200 to ~3800, and cuts over 8% off the
run time of those tests, without IMNSHO reducing the effectiveness of
the testing.

git-svn-id: svn://anonsvn.mit.edu/krb5/trunk@21064 dc483132-0cff-0310-8789-dd5450dbe970