Provide clipboard access through the VSCode API

[RoscoP]

• VSCode Version: 1.4.0
• OS Version: Windows 7

Feature Request:
It would be great to get access to the clipboard in the VSCode API. My use case is very simple, I want to be able to put specific text into the clipboard when a button is pressed (relative path to a file). I'm sure other extensions would benefit from clipboard access access as well.

[bpasero]

@jrieken fyi

[jrieken]

closing as duplicate of #217. Note that we don't have plan to expose the clipboard in the API but recommend the use of npm modules that do this, like: https://github.com/xavi-/node-copy-paste