[Proposal] Improve brace expansion dependencies

[zzarcon]

Ey guys I really like the new feature for asign dependencies with brace expansion see here like this:

something: function(){
    return this.get('baz.foo') + ' ' + this.get('baz.bar');
}.property('baz.{foo,bar}')

So I would love that the brace expansion also accepts properties like this:

Change value in each property of each array

.property('baz.{foo,bar}.@each')

.property('baz.{foo.@each,bar,other.@each}')

What do you think about this? thanks!

[rwjblue]

Closing in favor of PR (#4617).