Support for `clipboard=unnamed` / using system clipboard for unnamed register

A setting to use the unnamed register as alias for the * register. So yy for example copies to current line to the system clipboard, and p would insert from the clipboard.

Should be a user setting (e.g. useSystemClipboard), and disbaled by default.

Further readings:

• http://vim.wikia.com/wiki/Accessing_the_system_clipboard
• http://vimdoc.sourceforge.net/htmldoc/change.html#E354 (topic 7)

[aminroosta]

@rebornix Sure, I will send a pr tonight 😉

[bufke]

This doesn’t appear to be working for me. When enabled yank no longer seems to do anything. After a yank I’m unable to paste in the system or in VS Code (for instance p). Using Ubuntu 16.04. My settings are:

{
    "vim.useCtrlKeys": true,
    "vim.useSystemClipboard": true
}