[BUGFIX beta] Sync router.js, fix redirect issue

Occasionally leaf route redirects would report
as errors instead of just aborted transitions.
[BUGFIX beta] allow enumerable/any to match undefined as value
Merge pull request #4198 from machty/redirect-hook-fix

[BUGFIX beta] Sync router.js, fix redirect issue
Merge pull request #4144 from fwoeck/master

Allow enumerable/any to match undefined as value (issue #4139)