Shorten a few routine names to <= 16 characters long to fit in table.

 in DecodeTimeOnly(). Only present when seconds are not specified
 for input.

Rename date+time conversion to datetime to ensure less than 16 characters
 in routine name (required to fit in pg_proc table).

Before, char16 was missing last character for output.

Allow true/false, yes/no, 1/0. Throw elog warning if anything else.
Allow shorter strings, so "t", "tr", "tru" and "true" match "true".
Old behavior accepted anything starting with "t" as TRUE,
 everything else as FALSE.

Should have been here in time for 6.2.1 release...

Install compiled functions into $(LIBDIR)/contrib.
(Thanks to Brook Milligan <brook@trillium.NMSU.Edu>)

Leave all other input values to return FALSE.
In next version, do more checking for valid inputs for both TRUE and FALSE.

Allows the following example:
  select 'first string'
  '---'
  'last string';
 to be output as 'first string---last string'.

 Wrong function referenced in previous versions.

RelationIdCacheGetRelation() to flush relations from cache
in commit time.