ecpg thread test program

I have updated ecpg/test/test_thread.pgc to do an automated thread test.

First, update to current CVS. Then, run configure with
--enable-thread-safety, compile/install, then go to ecpg/test, and do a
'gmake', then run 'test_thread dbname'. It should return success or
failure.

I hope this program can be used to test threading on our various
platforms.

-- 
  Bruce Momjian                        |  http://candle.pha.pa.us
  pgman@candle.pha.pa.us               |  (610) 359-1001
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