[Form] [Locale] PHP 5.5 compatibility fixes

Bug fix: yes
Feature addition: no
Backwards compatibility break: no
Symfony2 tests pass: yes
Fixes the following tickets: N/A
Todo: None
License of the code: MIT
Documentation PR: N/A

IntlDateFormatter::setTimeZoneId() is deprecated in PHP 5.5, which results in E_DEPRECATED errors when using the date form type. This PR works around that.

Furthermore, the version_compare() tests used in locale to detect PHP 5.5 are broken with snapshot and Git builds of PHP. I've also committed a fix for those tests in this PR.