We can end up starting up without going through session initialization if
we are activated via D-Bus alone.

An alternative, if this should become problematic, would be to delay all
start-up procsesing options until the first activation or open request is
received by the EditorApplication.

Fixes #661

Fixes the warning:

W: org.gnome.TextEditor.desktop:25: url-redefined translate
   An URL of this type has already been defined.