Various compile errors concerning overflow due to shifts, unsigned, and bad prototypes, from Solaris, from Diab Jerius

of the array constants and in one of the loadable modules I posted some time
ago.

Submitted by: Massimo Dal Zotto <dz@cs.unitn.it>

Goals: reduce the difficulty of porting from platform to platform,
       release to release, but moving as much as possible into config.h

        - src/backend/access
                - no changes
        - src/backend/utils
                - mostly cosmetic changes
                - ESCAPE_PATCH Added
        - src/Makefile.global changes merged

The updating of array fields is broken in Postgres95-1.01, An array can
be only replaced with a new array but not have some elements modified.
This is caused by two bugs in the parser and in the array utilities.
Furthermore it is not possible to update array with a base type of
variable length.


- submitted by: Massimo Dal Zotto <dz@cs.unitn.it>