Fix a race manipulating file descriptors in the test suite.  Always close the connection before closing redirected stdout and stderr.  Make sure the connection and redirected files are both closed if a test fails.
Fix a comment.
Destroy locks on exit from test/format.
Cut release 1.6.3
Bump release version to 1.6.4 in develop branch.
Merge branch 'develop' into memrata
Add a final call to __wt_txn_refresh when a connection is closed so
the data-source can clean out its cache of values.