* Remove unneeded d.ts files from extensions
Moves most extensions to use the lib files for the standard library that typescript provides.
* Remove a few more node.d.ts references
**Bug**
When refreshing a webview, a slight flicker can sometime be seen. This is especially noticable when using the markdown preview.
**Fix**
Instead of replacing the content of the iframe for refresh, create a new iframe with the new content and do a swap to update.
Adds an initial implementation of scroll synrconization from the markdown preview to the editor. When the preview is scrolled, automatically scrolls the editor to reveal the same location.
This required adding a new supported reveal type `AtTop` in our API. This is already supported and used internally, but not really exposed in the public apis (except for the `revealLine` command).
* Support Local File Links from the Markdown Preview
Fixes#989
**Bug**
* `file://` links do not work in the markdown preview.
* `./file` and `/file` and `file` links do not work in the markdown preview.
**Fix**
For the first issue, allow `file://` links explicitly.
Add a custom link validator. If the incoming link has no scheme, try to resolve it relative to the current file or workspace. Likes like `/file` are relative to the workspace, while links like `file` or `./file` are relative to the current file.
* Fix reveal of source line on load in markdown preview
* Adds command to post a message to an html preview
**Bug**
There is currently no easy way to communicate with an html preview document after the preview has been created.
**Fix**
Adds a command called `vscode.htmlPreview.postMessage` to post a message to a visible html preview. This message will only be posted if the target preview is visible.
Inside the preview, the event is recieved using the standard dom event:
* Remove logging
* proto
Continue proto
* clean up rendering
* Gate prototype
* Fix gating
* Remove public command
* Change setting name
* Added current position indicator
* Reveal center
