Fixes and additions to Assets.
* Fixed error in AssetTagTrait that passed wrong logical path for children files.
* Assets::compileFile() now throws exception if file isn't found.
* Added logicalPath() method to File.
Fixed methods.
* setContentType() wasn't setting charset properly.
* Fixed contentType() method.
Changed controllers.
Action methods don't need to be declared in controllers, views will still be rendered.
Error fix.
* Content type is now set according to request format.