Make to_timestamp and friends skip leading spaces before an integer field,

even when not in FM mode.  This improves compatibility with Oracle and with
our pre-8.4 behavior, as per bug #4862.

Brendan Jurd

Add a couple of regression test cases for this.  In passing, get rid of the
labeling of the individual test cases; doesn't seem to be good for anything
except causing extra work when inserting a test...

Tom Lane