Add withCredentials flag to HttpDefaults

[hieronx]

withCredentials can also be enabled on all http requests by adding it to the list of default settings.

It's not part of the official AngularJS documentation, but it is referred to by several online tutorials and you can find it here in the official Angular 1.x specs: https://github.com/angular/angular.js/blob/291d7c467fba51a9cb89cbeee62202d51fe64b09/test/ng/httpSpec.js#L1886

inject(function($http, $rootScope) {
   $http.defaults.withCredentials = true;
   $http({ ... });
}

[jokade]

LGTM, thanks. WIll be included in 0.2.1 (to be published today).

[hieronx]

+1