Wow ... It was just in front of my face!
Reading the section "Settings headers" as @charlietfl said ... it's really simple.
http://docs.angularjs.org/api/ng.$http
Setting HTTP Headers The $http service will automatically add certain
HTTP headers to all requests. These defaults can be fully configured
by accessing the $httpProvider.defaults.headers configuration object,
which currently contains this default configuration:
To add or overwrite these defaults, simply add or remove a property
from these configuration objects. To add headers for an HTTP method
other than POST or PUT, simply add a new object with the lowercased
HTTP method name as the key, e.g.
$httpProvider.defaults.headers.post = { 'My-Header' : 'value' }
Example Code
var app = angular.module('app', ['app.controller', 'app.service']);
app.config(function ($httpProvider) {
$httpProvider.defaults.headers.post = { "X-Requested-With": "XMLHttpRequest", "__RequestVerificationToken": $('[name=__RequestVerificationToken]').val() };
});