[HACK] [WHAT] [NO] Fix Mac command-key shortcuts in modal dialogs

[iwehrman]

This terrible, horrible no-good pull request fixes Mac command-key shortcuts (like cmd-D to dismiss the save dialog) in modal dialogs. The problem arises from the operating system capturing keyboard events that correspond to shortcuts for menu commands. The shell handles these keyboard events and translates them into command names, which are translated into commands and executed at the JavaScript level. This hack intercepts these command names and, when a modal dialog is open, forwards them as shellCommand events which are handled by open modal dialogs. The shellCommand events are then translated into their corresponding key bindings (e.g., edit.duplicate --> Cmd-D), which are used to manufacture a corresponding keydown event, and which are immediately handed off to the modal dialog's keydown handler.

(You may wonder why the command name forwarded from the shell isn't immediately translated into a keyboard event. To do so requires importing KeyBindingManager into ShellAPI, which seems to cause a circular dependency that makes Brackets sad.)

So, yes, this is very ugly, but, hey, YOU CAN DISMISS SAVE DIALOGS WITH THE KEYBOARD!

[iwehrman]

[iwehrman]

See also #418.

[RaymondLim]

@iwehrman
Your changes work and we can now use Cmd-D and Cmd-. on Mac. But as you have said this hack is quite ugly and we may need to do a thorough clean up later on. So instead of landing this, I did implement the JS dialog modality with these two pull requests -- adobe/brackets-shell#268 and #4341

[iwehrman]

Closing this out in favor of of pull #4341 from @RaymondLim, which is, in contrast, not insane.