Rebased onto current master and fixed the privacy module build:
- privacy_item.hpp no longer includes privacy.hpp (it does not use the
Privacy class); this broke the circular include that left PrivacyItem
undeclared when privacy.hpp was reached first from privacy_item.cpp.
- privacy_item.cpp now includes gtkmm/label.h explicitly, since Gtk::Label
was previously only pulled in transitively via privacy.hpp.
Only consider a privacy module as visible if it is enabled in the
configuration. Otherwise, when screensharing or audio-in or audio-out is
in use but the associated module is not enabled, the privacy widget is
empty but still considered as visible.