Delete checkbox does not select all cards (version v0.2.32)

[PhillipsOwen]

the "check all" check box in the lower tray does not select all cards to delete.

steps to reproduce:

• open the site
• select the uppermost checkbox in the layer card area in the lower tray.
• note that not all cards are checked for delete.

[scrummish]

@PhillipsOwen this is ready for testing on checkbox-issues branch