Starting new architecture for WResponse
Merge remote-tracking branch 'origin/0.4' into response-model

Conflicts:
	system/WCore/WResponse.php
Merge branch '0.4' into response-model
New WResponse management and new model structure

- WRoute only deals with parameters (no more App and Args)
- WMain handles the response mode (first parameter received from WRoute)
- WResponseTheme and WResponseSerializer added
- A response is a plugin to WResponse
- Model in WRetriever returns params, signature and has-parent
- Added method WRetriever::getViewFromModel()
Removes $has_parent from Action signature
Fixes a bug on WRoute with extra slash not removed
Route calcul is done earlier for WSession
Fixes absolute links on ResponseSerializer and fixes a bug in admin modal

close #62
Merge pull request #81 from Creatiwity/response-model

Response model