throw error when angular-ui-router.js is loaded before angular.js

angular-ui-router.js cannot be loaded asynchronously with angular.  this change throws an error explaining such so that developers do not waste time trying to figure out what is meant by:

Error: [$injector:modulerr] Failed to instantiate module ui.router due to:
Error: [$injector:modulerr] Failed to instantiate module ui.router.state due to:
TypeError: undefined is not a function