Translated labels

Hi @isteven 

First - thank you for your great angular-multi-select control. I use it in my current project. 

In my current project I've the requirement that all labels are multilingual (inclusive the labels of the angular-multi-select control). So I've integrated the well-known component angular-translate as dependency - so we have the chance to translate all labels of angular-multi-select (i.e. 'Select all', 'Reset', 'Search', etc.) in any language. 

In my pull request you'll see the english and german translations.

What do you think about it? 

If you want, I will create a jsfiddle for you.

Thanks for your feedback.

Kind regards, patrick