refactor password strength directive, fix springloader property and i18n

- My first implementation of the password strength checker was a bit dirty.  
Now, instead of having the directive on the password input and modifying an element in the DOM, we use the directive as an element that we place where we want the strength bar to be and it will check the model of the password in the scope. This allows the directive to be testable and cleaner.  
Since the directive ````ng-minlength```` prevents the scope to update the password until it validates, the strength bar is only updated as soon as the user type at least 5 characters. Therefore, I don't hide the strength bar at startup any more.
- I added the property ````<springloaded.version>1.2.0.BUILD-20140214.165636-1</springloaded.version>```` in the _pom.xml which was removed (by mistake)
- I fixed the translation for the password form, the maxlength used to be 20, but the validation on the input said 50. I guess it's 50...