Fix PHP 5.5+ compatibility + require PHP 5.3+

Conflicts:
	.travis.yml
	data/bin/check_configuration.php
	lib/form/addon/sfFormObject.class.php
	lib/plugins/sfDoctrinePlugin/lib/form/sfFormFilterDoctrine.class.php
	lib/service/sfServiceContainer.class.php
	lib/util/sfInflector.class.php
	lib/vendor/lime/lime.php