pgsql: Convert Postgres arrays to Perl arrays on PL/perl input argument

Convert Postgres arrays to Perl arrays on PL/perl input arguments

More generally, arrays are turned in Perl array references, and row and
composite types are turned into Perl hash references.  This is done
recursively, in a way that's natural to every Perl programmer.

To avoid a backwards compatibility hit, the string representation of
each structure is also available if the function requests it.

Authors: Alexey Klyukin and Alex Hunsaker.
Some code cleanups by me.

Branch
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master

Details
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http://git.postgresql.org/pg/commitdiff/87bb2ade2ce646083f39d5ab3e3307490211ad04

Modified Files
--------------
doc/src/sgml/plperl.sgml                  |   70 +++-
src/pl/plperl/GNUmakefile                 |    2 +-
src/pl/plperl/Util.xs                     |   14 +
src/pl/plperl/expected/plperl.out         |  118 ++++--
src/pl/plperl/expected/plperl_array.out   |  222 +++++++++
src/pl/plperl/expected/plperl_trigger.out |  132 +++---
src/pl/plperl/expected/plperl_util.out    |   18 +
src/pl/plperl/plc_perlboot.pl             |   88 +++--
src/pl/plperl/plperl.c                    |  690 +++++++++++++++++++++--------
src/pl/plperl/plperl.h                    |    1 +
src/pl/plperl/sql/plperl.sql              |   47 ++-
src/pl/plperl/sql/plperl_array.sql        |  164 +++++++
src/pl/plperl/sql/plperl_trigger.sql      |   86 ++--
src/pl/plperl/sql/plperl_util.sql         |   12 +
14 files changed, 1296 insertions(+), 368 deletions(-)