Add unity app indicator support

[varlesh]

Notification working fine, but not systray icon.
Add suport please for indicator-messages.
OS:Ubuntu 14.04 Unity 32-bit
Venom: 0.2.0

[romansimakov]

+1

[varlesh]

Indicator show icon Venom if add key venom.desktop to com.canonical.indicator.messages.applications
But icon not flashing (when a message is received) and no show the number of messages.
And bug:
If enabled "option minimize to tray" Venom not showing after minimizing.

[naxuroqa]

Different window managers support different sets of features.
See http://askubuntu.com/questions/19846/adding-icon-to-the-system-tray-notification-area
Unity devs chose to create their own api called appindicator.

I'm not sure if I can access this api via dbus (so it wouldn't be a buildtime dependency) - If not, it's unlikely I will add support for it in the next time, since it would require to build ubuntu/unity only packages with an additional dependency to appindicator.

[nazar-pc]

Thanks, @freeniki, it works.
@naxuroqa, is it difficult to add record there automatically if it is not present?