replace dirname(__FILE__) by __DIR__

Since PHP 5.3 is now the requirement, we can use the __DIR__ magic constant instead of dirname(__FILE__) for a little extra performance.
Merge pull request #57 from mentalstring/master

Replace `dirname(__FILE__)` by `__DIR__` since PHP 5.3.4 is required
Use late static binding for config classes (PHP 5.3+)
Merge pull request #25 from LExpress/late-static-config

Use late static binding for config classes (PHP 5.3+)
PHP built-in webserver compatibility

`sf_cli` should be `false` when running with PHP built-in webserver (PHP_SAPI == "cli-server"). It is a web-environment, not CLI, though it is initiated with CLI command.
Merge pull request #58 from e1himself/patch-1

PHP built-in webserver compatibility
remove doctrine plugin
add propel to session storage
don't cache json response
don't set cli for built-in web server
support PATCH requests