Allow PDO drivers custom methods to trigger errors/exceptions

Moved a few definitions from php_pdo_int.h to a new php_pdo_error.h
header file that can be included if drivers need PDO's own error
handling to be triggered within custom methods (e.g. PDO::pgsqlLOBOpen).
Refactored custom PDO_pgsql methods to trigger errors/exceptions

BC Break: the custom methods were previously just return false on
failure. Now they throw an exception with a proper error message.
An hopefully welcome improvement, but some application might be
depending on the old behaviour. FWIW the PDO::pgsqlCopy* methods
are not documented, even though they are available since 5.3.x.
Fixed Bug #42614 (PDO_pgsql: add pg_get_notify support)
fix CVE-2013-2110 - use correct formula to calculate string size
Merge branch 'PHP-5.3' into PHP-5.4

* PHP-5.3:
  fix CVE-2013-2110 - use correct formula to calculate string size
Merge branch 'PHP-5.4' into PHP-5.5

* PHP-5.4:
  fix CVE-2013-2110 - use correct formula to calculate string size
Merge branch 'PHP-5.5'

* PHP-5.5:
  fix CVE-2013-2110 - use correct formula to calculate string size
Fixed bug #64960 (Segfault in gc_zval_possible_root)
Merge branch 'PHP-5.3' into PHP-5.4
Update NEWS
Merge branch 'PHP-5.4' into PHP-5.5
Update NEWS
Merge branch 'PHP-5.5'
Add NEWS for PHP 5.3.26
Merge branch 'PHP-5.3' into PHP-5.4
Merge branch 'PHP-5.4' into PHP-5.5
Merge branch 'PHP-5.5'