libdbusmenu-qt had an awful bug in it that meant it would spawn a nested
event loop when updating a menu.
In order to fix StatusNotifierItem I ended up making a fork of the 3
small classes that we needed and applying a fix, whilst we waited for
upstream.
We also were including a complicated library+plugin that handled import
and exporting, just to do importing which is rather pointless.
When appmenu support was restored, we ended up re-linking the original
dbusmenu-qt library. The original still had the same bug, manifesting in
a whole new way of Kate's bookmarks menu automatically closing when you
click on it.
This patch shares the same libdbusmenu-qt lib we have for the SNI
dataengine with the one for appmenu.