Improve resource management for curl handle

Previous implementation was using its own refcounting (uses field of
the php_curl struct). zend_list_add/remove already implements its own
refcount, so we don't need to use an other one.
Merge branch 'PHP-5.5'

* PHP-5.5:
  Improve resource management for curl handle
Bug #63699 performance improvements for ext/date by only validating timezone when timezone is set
Merge branch 'PHP-5.5'
Bug #63699: performance improvements for varios ext/date functions
Adding test from 5.5
bump year
Merge branch 'PHP-5.3' into PHP-5.4
Merge branch 'PHP-5.4' of git.php.net:php-src into PHP-5.4
bump year
Bug #23955: allow specifiy max age for setcookie()
Merge branch 'PHP-5.4' into PHP-5.5
Merge branch 'PHP-5.5'
Merge branch 'PHP-5.5' of git.php.net:php-src into PHP-5.5
Merge branch 'PHP-5.5'
Coding style, ANSI C compatibility
Merge branch 'PHP-5.4' into PHP-5.5
Merge branch 'PHP-5.5'
Fixed bug #55397: Comparsion of incomplete DateTime causes SIGSEGV.
Adding test for bug #63462