FOO_REQD=1.0 being converted to foo>=1.0, one can now directly specify
the dependency pattern as FOO_DEPENDS=foo>=1.0. This allows things like
JPEG_DEPENDS=jpeg-6b, or fancier expressions like for postgresql-lib.
Change existing FOO_REQD definitions in Makefiles to FOO_DEPENDS.
PL/Perl allows you to write functions in the Perl programming language
that may be used in SQL queries as if they were built into Postgres.
The PL/Perl intepreter is a full Perl interpreter. However, certain
operations have been disabled in order to maintain the security of the
system.