Routing: Allow access to properties of `$routeParams` in `onActivate` expression of routes

[tbosch]

This idea came up in issue #103, see the example there.

Tobias

[mlegenhausen]

+1 Another cool feature would it be to directly inject the url parameters in the onActivate method. E.g.

$routeProvider.when('/:someUrlParam', {
  resolve: {
    someResolveParam: 'foo'
  },
  onActivate: 'init(someUrlParam, someResolveParam)'
}