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.
Bringing CSS up to this decade's standards.

Here are some tweaks to the phpinfo() styling, since this really hasn't
been touched in almost a decade:
- color codes are shortened
- table width is bigger and handled via CSS
- fix so that long INI entries don't make the layout super wide
- bgcolor for "Additional Modules" wasn't set
- fix my email address

Signed-off-by: Colin Viebrock <colin@viebrock.ca>
Bump up table width a bit more and make columns consistent
fix for scrolling, other minor tweaks
update Zend Engine logo as per Zeev, and tweak PHP logos ... :)
Fix DateInterval->days value
when object was created not from DateTime::diff()
Remove semicolon
Add schema default/fixed value support

Added support for adding fixed/default values during XSD validation
and added/updated associated tests
zend_register_bool_constant patch
use Z_* family macros
zend_API.h included
ZVAL_* family in use
zend_register_null_constant
fixed zend_register_bool_constant usage in macros
use REGISTER_MAIN_* in zend_register_standard_constants
Merge branch 'PHP-5.5'

* PHP-5.5:
(re)allow WBMP detection with system libgd
provide getbmi and skipheader not exported functions in gd_compat.
enable WebP with system libgd when available
Merge branch 'PHP-5.5'

* PHP-5.5:
  enable WebP with system libgd when available
  (re)allow WBMP detection with system libgd provide getbmi and skipheader not exported functions in gd_compat.
fix copy/paste in error message
Merge branch 'PHP-5.5'

* PHP-5.5:
  fix copy/paste in error message
Fixed incorrect check. SEND_REF may be executed before DO_FCALL when EX(function_state).function is not yet set to the calling function.