Revert "connect to modified instead of up/down/focus-lost"

This reverts commit 44bfe8fa

Revert "listening to modify is sufficient to get all changes"

This reverts commit 5c0bb108

we probably need to distinguish a modify vs update signal to
get what I wanted here. Back to the original mode for now.

Change-Id: I51ebfc96b3a06cf09905f4a311d526f23ce371f1
Reviewed-on: https://gerrit.libreoffice.org/46958Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>