This reverts part of 745c7bce.
The current behavior of affecting only the current document is
useless, given that the same can be done by editing the
corresponding styles. Actually I'm pretty sure that's why the
wiki flagged the "Current document only" option as unnecessary.
So let's go back to saving for all documents.

Change-Id: I7ed9609bc93ae519ac89a6e6080a3b37b09633d8