ECPG - Remove need for "AT connection" when using threads

Attached diff improves the handling of connections in ecpg when threading is
used. The "current connection" is now the last connection made/set for the
thread in question - not the absolute last connection made/set (over all
threads in the process). This change removes the tedious need to always use
"AT connection" for each and every EXEC SQL call (an item on the TODO).

The "test_thread_implicit" test program added in the last email will
function as intended with this patch.

Thanks, L.

----- Original Message -----
From: Lee Kindness
To: pgsql-patches(at)postgresql(dot)org
Cc: Bruce Momjian ; Lee Kindness ; Shridhar Daithankar
Sent: Saturday, March 06, 2004 3:07 PM
Subject: ECPG: Update tests & memory leak fix

See attached diff which corrects a per-thread memory leak in libecpg and
changes the thread test program to create a user defined number of threads.
Also attached tar.gz adds an additional thread test, which currently does
NOT work as expected and is one of the cases Shridar and I will be looking
at (removing need for AT xxx on every EXEC SQL).

Note, the updated test shows that ECPG currently DOES support the
specification of connection names by host variables (not only static strings
as I had said previously).

Thanks, L.