0.6.0: PSR2, PSR4, postJson()

• Namespace is now Resty\Resty
• Added Resty::postJson() method to make sending a JSON body easier
• Added Resty::jsonToArray($bool) to have response JSON decoded to Array (default is still stdClass object)
• Code now PSR2 compliant
• Supports PSR4 autoloaders
• FUnit now included via composer; no more git submodule
• Fix a couple bugs with raising exceptions, empty $meta['wrapper_data']
• Make all existing tests pass, and add new tests