We compile using the alwaysStrict flag so these directives are not needed

* Webview api

* Cleaning up markdown webview

* Hooking up dispose

* Fix some merge errors

* Use custom context key to show markdown title bar contributions

* Add basic on focus and on blur events

* Fixing find widget in webview

* Hookup _isDisposed

* Use new extension resource scheme to load markdown extension resources

* Documenting keep alive

Initialize extension host customers only after a connection has been established with the extension host; retire IThreadService