Add create_sid to session_set_save_handler and SessionHandler

A lot of code already existed to allow a custom create_sid handler, but
lacked a specific implementation.

Therefore I have added a 7th (optional) argument
session_set_save_handler, to allow a user function to be supplied for
session id generation.

If a create_sid function is not supplied, the default function is
called in its absence to preserve backwards compatibility.

Likewise create_sid only added to SessionHandler class, and not the
interface to maintain backwards compatibility. If the result is not
overridden, the default is called.
Tests, fixes and optimisations

* Amended existing tests to cater for new functionality.
* Implemented fixes and optimisations recommended by NikiC
* Added create_sid to the registered interface. This was breaking
tests. It also now breaks BC for people implementing the interface
directly instead of extending the class.
Minium changes to allow PDO_OCI to build with Oracle Database 12c libraries.
(note OCI8 already builds with Oracle Database 12c)
Merge branch 'configure12c' into PHP-5.4

* configure12c:
  Minium changes to allow PDO_OCI to build with Oracle Database 12c libraries. (note OCI8 already builds with Oracle Database 12c)
Merge branch 'PHP-5.4' into PHP-5.5

* PHP-5.4:
  Minium changes to allow PDO_OCI to build with Oracle Database 12c libraries. (note OCI8 already builds with Oracle Database 12c)
Merge branch 'PHP-5.4'

* PHP-5.4:
  Minium changes to allow PDO_OCI to build with Oracle Database 12c libraries. (note OCI8 already builds with Oracle Database 12c)
- Fixed bug #60732 (php_error_docref links to invalid pages) patch by: Jakub Vrana
Merge branch 'PHP-5.4' into PHP-5.5

* PHP-5.4:
  - Fixed bug #60732 (php_error_docref links to invalid pages) patch by: Jakub Vrana
Merge branch 'PHP-5.5'

* PHP-5.5:
  - Fixed bug #60732 (php_error_docref links to invalid pages) patch by: Jakub Vrana
- BFN
Merge branch 'PHP-5.4' of https://git.php.net/repository/php-src into PHP-5.4

* 'PHP-5.4' of https://git.php.net/repository/php-src:
  - BFN
  - Fixed bug #60732 (php_error_docref links to invalid pages) patch by: Jakub Vrana
Merge branch 'PHP-5.5' of https://git.php.net/repository/php-src into PHP-5.5

* 'PHP-5.5' of https://git.php.net/repository/php-src:
  - Fixed bug #60732 (php_error_docref links to invalid pages) patch by: Jakub Vrana
Merge branch 'master' of https://git.php.net/repository/php-src

* 'master' of https://git.php.net/repository/php-src:
  - Fixed bug #60732 (php_error_docref links to invalid pages) patch by: Jakub Vrana
Merge branch 'PHP-5.4' into PHP-5.5

* PHP-5.4:
  - BFN
Merge branch 'PHP-5.4'

* PHP-5.4:
  - BFN
- Fixed bug #62964 (Possible XSS on "Registered stream filters" info) patch by: david at nnucomputerwhiz dot com
Merge branch 'PHP-5.4' into PHP-5.5

* PHP-5.4:
  - Fixed bug #62964 (Possible XSS on "Registered stream filters" info) patch by: david at nnucomputerwhiz dot com
  - BFN
Merge branch 'PHP-5.5'

* PHP-5.5:
  - Fixed bug #62964 (Possible XSS on "Registered stream filters" info) patch by: david at nnucomputerwhiz dot com
  - BFN
Merge branch 'master' of git.php.net:/php-src
Merge branch 'PHP-5.5' of git.php.net:/php-src into PHP-5.5