Ensure parent permissions are evaluated only once

[joeljeske]

This fixes Goal 1 marked #338.

The issue was, that if I had a state hierarchy like,

$stateProvider
  .state('root', {
    ...
    data: {
      permissions: {
        only: 'isLoggedIn'
      }
    }
  })
  .state('root.child', {
    ...
  });

then, upon $state.go('root'), the isLoggedIn permission would evaluate twice, once for the parent and once for the child.

This was due to UI-Router making the data property of states prototypically inherit from their parent. Thus if a child does not specify its own permissions property, then it would use its parent property.

This was easily fixed by making sure we would only use the permissions from a state that hasOwnProperty('permissions')

[coveralls]

Coverage remained the same at 99.324% when pulling d947c33 on joeljeske:feature/multiple-permission-evaluation into 7263962 on Narzerus:development.

[masterspambot]

Using only hasOwnProperty should be sufficient I think. No need to recheck by calling property itself afterwards.

[joeljeske]

Sure, I generally agree except if someone uses null as the permissions value. Edge case though, I guess.