code refactoring: integration with Shelf
Improved API: error handlers can return a shelf.Response or Future<shelf.Response>; fixes.
Added serveRequests method
Added new tests
Improved API: Routes can return shelf.Response or Future<shelf.Response>
Updated README.md
Small fixes to the request flow
Added @DefaultRoute annotation; Multiple routes with same path and different http methods are now allowed.
Updated CHANGELOG.md
Merge pull request #14 from luizmineo/v0.5

V0.5