docs($http): makes clear $httpProvider.defaults are available at run-time
docs($http): makes clear $httpProvider.defaults are available at run-time

Clarifies some confusion around $http.defaults existing and able to be modified
at run-time, for when run-time services may be needed in a transformation.

Closes #5559
Closes #5630

ammula88/angular.js,ammula88/angular.js,ammula88/angular.js,ammula88/angular.js,ammula88/angular.js