bookmark: deprecate direct update of a bookmark value
This changeset was part of an older series preventing direct update of the
bookmarks store without the change being tracked by a transaction. For some
unclear reason, this was not sent to the list. So we are sending it now.
Initial series: 3325c7dcabaa+08bf0ebc6c8e+712a85b3677f.
We want to channel all bookmarks update through 'applychanges' so let's remove
more way to work around this function.
#require docutils gettext
$ $TESTDIR/check-gendoc it
checking for parse errors