Message punctuation and pluralization fixes
Document how auto_explain.log_timing can be changed.
Docs:  Document to_*() Julian values are integers
Backpatch to 9.3.
Per request from Marc Dahn
docs:  mention Julian is midnight _UTC_
(Yes, there was no UTC back then, but we compute it that way.)
Backpatch to 9.3.
PL/Python: Adjust the regression tests for Python 3.3

Similar to 2cfb1c6f77734db81b6e74bcae630f93b94f69be, the order in which
dictionary elements are printed is not reliable.  This reappeared in the
tests of the string representation of result objects.  Reduce the test
case to one result set column so that there is no question of order.
Merge branch 'master' into fpw-compress