Merge pull request flightphp#395 from merkuriy/JsonSerializableCollec…

…tion

Added JsonSerializable for util/Collection

Merge pull request flightphp#409 from pluveto/patch-1

Trim url

Bump version.

Prevent response from sending more than once.

Fix conflict with external error handlers.

Response content-length header should use mbstring if available.

Removed another case of $route passing. Updated tests.

Remove $route from parameter list, only pass when dispatching callback.

Removed JSON encode depth parameter to keep PHP 5.3 compatibility.

Moved map method check to Engine. Added get method to Loader. Added n…

…ew tests.