Bug 54438: First part of core change 97caae596: support time/data/mark elements

These are now allowed by default in the core sanitizer, so allow them in
Parsoid too.

Other parts of 97caae596 are not done yet. Will leave the bug open until the
other changes are ported too.

Change-Id: I668ad89aad9f6c798645d081b5971719175b7ea5
Merge "Bug 54438: First part of core change 97caae596: support time/data/mark elements"