Show case properties in the "Case History" table of the Case Export page by default

Previously, you had to check the "show advanced and deleted properties" box to see all properties in the case history table. Now, all of those properties will be shown regardless of whether the box is checked or not. (The "Cases" table is unaffected).

Addresses this ticket:
http://manage.dimagi.com/default.asp?123010#695770
I wasn't sure if this was the best way to check that we're in the case history table or not. If someone knows a better way I'd love to hear it.