[monaco] Integrate with menus / commands

[svenefftinge]

• The actions provided by monaco should be registered with our CommandRegistry.
• A context menu for monaco editors should be registered with MenuModelRegistry.
• monaco context menu should be deactivated and replaced with ours

[kittaakos]

During a short investigation, Google Docs, LucidChart and Cloud9 IDE were examined. It turned out; there is no ultimate solution for accessing the native clipboard from the browser, so to support the copy/cut/paste actions in all major browsers, we would need to have browser specific implementations.

We decided to follow the Monaco pattern and support the main- and context menu based copy/cut/paste only in the Electron-based application.

Here comes a list of threads which provide more information on the native clipboard access.

• https://www.lucidchart.com/techblog/2014/12/02/definitive-guide-copying-pasting-javascript/
• https://blog.dmbcllc.com/cross-browser-javascript-copy-and-paste/
• https://jsfiddle.net/kittaakos/ftr8bgun/3/
• Edit actions are available only in IE microsoft/monaco-editor#391
• http://stackoverflow.com/questions/9658282/javascript-cut-copy-paste-to-clipboard-how-did-google-solve-it
• https://github.com/c9/core/blob/master/plugins/c9.ide.clipboard/clipboard.js#L249

[kittaakos]

It would be great to show the associated key binding for a command in the (context-) menu if any. Just like Monaco does here.

Moved to #37.

[kittaakos]

PR: https://github.com/TypeFox/Theia/pull/35

[kittaakos]

Closed via #35.