Avoid a lockup when adding an entry to the catalog
Hang onto the drawObject and icons when needed
Revert "Hang onto the drawObject and icons when needed"

This reverts commit 9d9c9a9ceb11ba4c88f3c8fae10b705b64221651.
Retain icons/objects when creating object cell icons

Remove code that modifies the NSImage
Merge pull request #1410 from quicksilver/lockfix

Avoid a lockup when adding an entry to the catalog. Fixes #1388