* destroy viewmodel when editor is closed and add example
* support retainContextWhenHidden option for webview component
* fix breaking change from master
* dispose html element during dispose
* add more comments
* Add proposed API for model view editors
* Initial working model view editor
* Add extension demo
* Revert "Add extension demo"
This reverts commit 10d3b720ad347919dd5668a339da8e96e26b2b82.
* view model editor and add the support for register content
* clean up the code
* fix editor issues where you register more than one content
* formating
* remove unused imports
* addressed comments
* address comments2
* address comment3
