Fixed bug #62857 (bytea test failures)

Postgres 9.1+ test fixes. Tests were failing due to the default
standard_conforming_strings GUC being changed to on. Also the
pg_escape_bytea test was encoding the data before estabilishing
a connection, thus falling back to the old escaping type which
isn't properly handled by the backend when using a default
configuration.

I haven't updated the NEWS file as it's just test fixes.
Merge branch 'PHP-5.3' into PHP-5.4

* PHP-5.3:
  Fixed bug #62857 (bytea test failures)
Merge branch 'PHP-5.4' into PHP-5.5

* PHP-5.4:
  Fixed bug #62857 (bytea test failures)
Merge branch 'PHP-5.5'

* PHP-5.5:
  Fixed bug #62857 (bytea test failures)
Fixed bug #64609 (pg_convert enum type support)
Merge branch 'PHP-5.3' into PHP-5.4

* PHP-5.3:
  Fixed bug #64609 (pg_convert enum type support)
Merge branch 'PHP-5.4' into PHP-5.5

* PHP-5.4:
  Fixed bug #64609 (pg_convert enum type support)
Merge branch 'PHP-5.5'

* PHP-5.5:
  Fixed bug #64609 (pg_convert enum type support)
Add new function string_is_ascii