Add new (App/Window/View)Activatable interfaces for plugins

Currently only the modelines and filebrowser plugins are updated to these new
interfaces

debian/xed-common.install

@@ -1,7 +1,7 @@
 usr/share/appdata
+usr/share/xed/plugins
 usr/share/glib-2.0
 usr/share/help
 usr/share/locale
 usr/share/xed/icons
-usr/share/xed/plugins
 usr/share/xed/ui/

debian/xed.install

@@ -1,8 +1,7 @@
 usr/bin/xed
-usr/lib/*/xed/plugins/*.plugin
 usr/lib/*/xed/girepository-1.0/
+usr/lib/xed/xed-bugreport.sh
 usr/lib/*/xed/plugins/*.plugin
 usr/lib/*/xed/plugins/*.so
-usr/lib/xed/xed-bugreport.sh
 usr/share/applications/xed.desktop
 usr/share/man/