0.4.0

API improvements and refactoring.

Changelog:

• Minor Autoloader improvement
• Major Router refactoring using method extraction
• Session objects can now be accessed like arrays, and as a result through
  their parent Request objects in the same way as other request data.
• Response refactoring, also removed Response::addContent()
• Removed redundant Tools::processPost()
• Added ContainerInterface::all() and SessionInterface::has()
• Container now automatically injects itself to any ContainerAwareInterface
  implementors that it instantiates
• Simplified Request/Response API