Revision 4860

Intermediate commit.  This should speed up working on long multipage
tests by not translating pages that aren't on the current page unless
we're grading or checking the test.

There is still a bug in the GatewayQuiz module when dealing with
multipage, multiattempt tests, however.  Management of the grading/
previewing state isn't being handled correctly, so the logic for
that needs to be reworked.