Homestyx hydra

R1:0597aba33ec1

Add hard stops on empty batch edit sets

Summary:
Ref T8637. If a user tries to batch edit a list of tasks which can't be edited, we fall through to `withIDs(array())`, which can affect //everything//.

Explicitly stop batch editing if we don't have valid IDs or valid tasks.

The UI sort-of warns you that something is wrong, but this is ultimately a pretty severe UX issue. I'll fix the underlying Query in the next diff.

Test Plan: Tried to batch edit a list of tasks I didn't have permission to edit.
Repository: R1 hydra
Commit Date: Jun 22 2015