fix(dialog-controller): fix the class interface
fix(dialog-controller): fix the class interface

Fixes #82.
Also expose the 'settings' attribute of 'DialogController' class so that
it can be included in the 'd.ts' file.

aurelia/dialog,rockResolve/dialog,StrahilKazlachev/dialog,aurelia/dialog,rockResolve/dialog,StrahilKazlachev/dialog