feat(dateParser): add dateParser service

[bekos]

Will appreciate if anyone is interested to review or add tests.

[Foxandxss]

Angular team is suggesting to not use the $ in non-core services (See here). We are using it on a lot of places and some of them ($modal) could bring breaking changes. I think that at least we should avoid creating new services with the $.

[bekos]

@Foxandxss This makes sense, thx.

[chrisirhc]

Very nice. I just reviewed it. Clean implementation. Looks good to me.

[bekos]

I remove the $ from service as @Foxandxss suggested.

@chrisirhc Thx for the review and your time. I also added edge case validation, like 29/02/2014, 31 April etc, that cannot be "catched" with regex as it is now.

[pkozlowski-opensource]

Yay! This should considerably cut down number of issues opened for date picker! Great job!

[cyberwombat]

Shouldn't this provide support to initialize the datepicker with a string value? It seems that the validator is getting in the way of that. If I add a directive such as:

angular.module('app').directive('datepickerPopup', [function() {
  return {
    restrict: 'EA',
    require: 'ngModel',
    link: function(scope, element, attrs, ngModel) {
      ngModel.$validators = [];
    }
  };
}]);

I can now load using a date string and it will still validate input. Not sure what is doing the validation but it now seems to a) accept an ISO string as input and b) prevent me from entering anything but a valid date in the correct format. I admit I am a little confused as to where this validator is coming from but that is the apparent effect I see.