draft idea of action based responses
Renamed some folders to fit changed app structure.
implementation of Response tied to actions

Result of a discussion with @qiangxue
- there is not global Yii::$app->response anymore, every action has
  dedicated response class
- implementation allows using HMVC pattern now, nested actions do not
  interfer
Changed existing code to match the changes regarding response
Merge pull request #547 from suralc/advanced-rename

Renamed some folders to fit changed app structure.
Merge pull request #548 from cebe/action-response

implementation of Response tied to actions
Revert "Merge pull request #548 from cebe/action-response"

This reverts commit 9d7597d61a51ae7030b667f740c2a97471cf7f6e, reversing
changes made to 6b6390f72b6a6010cfbe614aab236a90d10b1a00.
Fixes issue #545: PageCache doesn't work.
Improve application speed by using classMap for autoloader
moved classMap to separate file
rename classMap.php -> classes.php
Better handling of sending response content.
Implemented language negotiation.
Implemented Request::getAcceptedContentTypes().
updated basic app dependencies
fixes #549: ability to use HTMLPurifier multiple times
Merge pull request #550 from cebe/speed

Improve application speed by using classMap for autoloader
Fixed jsonp response handling.
Removed composer.lock from all apps. Currently it creates more problems since framework code changes rapidly.
fixed advanced app aliases
fixed advanced app contact form