Add option to disable dialog click-outside-to-close

[jcmoore0]

Bug, feature request, or proposal: Feature

What is the expected behavior? Would like a "Modal" behavior where the Dialog does not close when clicking outside of the container.

What is the current behavior? Clicking outside the dialog container closes MdDialogRef. I would like to be able to turn disable this, so the user may not click outside and is only allowed to interact with the most recent "highest z-index" MdDialog open. We use one dialog on top of another.

What are the steps to reproduce? Click outside the dialog container.

What is the use-case or motivation for changing an existing behavior?

Which versions of Angular, Material, OS, browsers are affected?

Is there anything else we should know?

[JanStureNielsen]

Dup of #114

[aciccarello]

@jcmoore0, Your issue is a bit hard to read. Maybe separating your answers from the questions (so they are not bold) will make it easier. Also, a more descriptive title would be good. As far as I can tell this is not a duplicate.

Clicking outside the dialog container closes MdDialogRef. I would like to be able to turn disable this, so the user may not click outside and is only allowed to interact with the most recent "highest z-index" MdDialog open. We use one dialog on top of another.

Is there a way to avoid having multiple dialog boxes on top of each other?