Merge pull request #158 from chives/dev-crud

Removed unused contexts and controllers
Added documentation of changes in 1.1
Renamed Admin\ElementInterface to Admin\Element
Removed usage of deprecated interface from resource-repository-bundle
Moved doctrine DisplayElement to proper namespace
Extract common doctrine elements' methods to traits
CS fixes in display component
FormEvent and ListEvent now require interfaces instead of classes
ResourceRepository\Element now implements RedirectableElement
Remove CRUDEvents
Removed ResourceEvents in favour of FormEvents
Extract common form request handlers code into abstract classes