Hijra: Use indicator framework

[أحمد المحمودي (Ahmed El-Mahmoudy)]

This application contains an applet that displays the date according to Hijri (arabic) calendar. When the applet icon is clicked, it brings a window that displays the Hijri calendar along with the corresponding Gregorian dates (screenshot of that window is attached). The package is actually split into a python library (python-hijra) and the applet.

   The notification area will be deprecated in Natty's default desktop. So it is needed to make use of the indicator framework:

     https://wiki.ubuntu.com/DesktopExperienceTeam/ApplicationIndicators

   Rather than just doing a straight switch from GtkStatusIcon to Application Indicator, advice is sought about whether the functionality could be integrated into the calendar grouping menu. It is not necessary to modify the applet package, I was thinking that maybe there can be an option in the calendar menu to either use the Gregorian or the Hijri (or maybe any other) calendar system for displaying dates. In that case there are several libraries that can be used for the case of Hijri calendar system:

python-hijra, libitl, or libkal (the latter doesn't seem to be actively maintained upstream)