tab selection from controllers

[just-boris]

I refactor directive api.
This approach makes code simply and clear, thanks

[ajoslin]

Hey again boris,

Thanks for refactoring it. It looks good, just a couple things:

1. Could you change 'selected' to 'active'? Since accordion and carousel use 'active' attribute, it's more consistent.
2. Why not just use '=' binding for the attribute? You're basically making it yourself (eg scope: { 'active': '=' })
3. Could you add a few more unit tests for weird cases? Like when multiple panes evaluate to active=true

[just-boris]

1. Done. But you using "selected" property to bind class, because I renamed only attribute name.
2. It makes selected attrubute optional. Angular.js has issue directives that have '=' binding, changing scope value causes error if not specified(optional) angular/angular.js#1435 about it
3. Added 2 test cases: multiple set active=true and set active=false for all tabs

[ajoslin]

You're right about the '=' binding. It looks good to me, Boris :-). Thanks!

Landed in a75a85d