Hijack `UI.registerHelper`

This is necessary to hijack global helpers added after zones package
Add query to cursor methods info
Fix tracking global helper info
Use proper type values for iron-router hooks
Check whether the event handler is a function
Fix missing ownerInfo bug for Cursor.forEach/map
Fix observe/observeChanges bug

Set correct info type
Add missing data
Merge pull request #42 from meteorhacks/bug-fixes

Add missing features