ObjectChooser: preserve filter type

When the ObjectChooser is called with the filter_type=FILTER_TYPE_MIME_BY_ACTIVITY
the filter_type was replaced by FILTER_TYPE_ACTIVITY.
This patch preserve the value used, if not filter type was selected,
use FILTER_TYPE_ACTIVITY.

Signd-off-by: Gonzalo Odiard <godiard@sugarlabs.org>
Added input box for social-help server in control panel.
Added a dbus method to delegate function calls.
Added keyboard shorcut for social-help (alt+shift+c).
Added the code for launching social help.

The code also communicates with the forum router to determine the
correct url to launch inside social-help.
Fix social help server URL
Add social help under the activity icon in the frame
Merge branch 'prasoon2211-social_sugar_final' of https://github.com/SAMdroid-apps/sugar into SAMdroid-apps-prasoon2211-social_sugar_final
Merge branch 'SAMdroid-apps-prasoon2211-social_sugar_final' into social_sugar_final