Revision 1641526

DERBY-4057 Space is not reclaimed if transaction is rolled back

a few changes to make the ClobReclamationTest better behaved across a variety
of platforms.  The test tries to measure background thread behavior, and needs
to allow for machines/jvms that might be single threaded and slow.  

In one case added a sleep after all aborts to allow the background thread
to catch up and mark all pages but head one free.  

In other case added more to the fudge factor of how much immediate insert
might progress before background thread can catch up and make free page 
available.  If this does not work may just need to add sleep after every 
insert.