geoclue-2.0 robustness

[sunweaver]

The geoclue-2.0 bit in display indicator requires a user daemon running (/usr/lib/geoclue-2.0/demos/agent).

This agent can be used to kill geoclue-2.0 service access (kill the daemon, then there are no location services available anymore via geoclue-2.0).

If someone choose to disable the geoclue-2.0 agent (launched via XDG autostart), display indicator should silently ignore missing geolocation support and run happily without it (hiding the geo location based features).

This also goes further, the indicator tears its renderer down if geoclue-2.0 agent is not running, e.g. in MATE:

• Log into a normal MATE session
• kill /usr/lib/geoclue-2.0/demos/agent
• (make sure it does not come back)
• kill the display indicator process
• launch the display indicator again via a terminal
• (icon appears)
• click on the display indicator icon ----> BOOOM (mate-indicator-applet gone)
• when mate-indicator-applet comes back (and display indicator is already running), one can click on the display indicator icon and menus appear...