#### Bug, feature request, or proposal:
feature request

#### What is the expected behavior?
I'd like to use something like this (just like `mat-menu`):
```
Open it

Dialog Title

Content


Cancel
Confirm

```

#### What is the current behavior?
Doesn't exist as fat as I have seen in the docs and source code.

#### What are the steps to reproduce?
I've created a small component which demonstrates what I'm looking for:
https://stackblitz.com/edit/angular-material2-issue-tp5aej?file=app%2Fapp.component.html
(I didn't get `mat-dialog-close` working with the projection, though I chose to just add a method to my dialog component)

#### What is the use-case or motivation for changing an existing behavior?
There are many use cases where I just want a very simple dialog, and don't want to write 30 lines of code.

#### Which versions of Angular, Material, OS, TypeScript, browsers are affected?
Angular 6 beta
Material 6 beta

Inizia dall’esempio StackBlitz collegato, in particolare da app/app.component.html, e confronta l’uso inline richiesto di mat-dialog con la documentazione e il codice sorgente esistenti del dialog di Material. Determina se è possibile supportare il contenuto proiettato e mat-dialog-close, quindi definisci l’API e i test necessari per aprire il dialog e restituire il risultato selezionato.

Scritto dal modello di indicizzazione a partire dal testo della issue.