Make fast promotion the default promotion mode.
Continue to allow a request for synchronous
checkpoints as a mechanism in case of problems.
Fix assertion failure for REFRESH MATERIALIZED VIEW in PL.

This was due to incomplete implementation of rowcount reporting
for RMV, which was due to initial waffling on whether it should
be provided.  It seems unlikely to be a useful or universally
available  number as more sophisticated techniques for maintaining
matviews are added, so remove the partial support rather than
completing it.

Per report of Jeevan Chalke, but with a different fix
Add missing #include.

On non-Windows systems, sys/time.h was pulled in by portability/instr_time.h,
which pulled in time.h. We certainly should include time.h directly, since
we're using time(2), but the indirect include masked the problem on most
platforms.

Andres Freund
PL/pgSQL doc: Add example for RETURN QUERY

Erwin Brandstetter and Pavel Stěhule
initdb: Improve some messages
pg_basebackup: Add missing newlines at end of lines