FishEye watches do not respect filters

Creating a watch from a fisheye source page doesn't work as expected.

Steps to reproduce:

1. Visit a repository's activity stream
2. Filter based on branch name
   • Notice that the activity stream is reloaded correctly
   • Url for watch seems to indicate it would work
3. Add watch for the constrained path
4. FishEye redirects back to the unconstrained activity stream and the wrong watch is set

Originally reported: http://forums.atlassian.com/thread.jspa?messageID=257323073