Send a file to multiple friends: Fixes #1471

[devAbnull]

pop-up window with the listview of the friends online is displayed,
multiple friends cn be selected and pressing the send toolbutton sends the file to selected friends.

Note: used the PopWindow class of sugar3.graphics as implemented in commit-> sugar-toolkit-gtk3:3d61134

[samdroid-apps]

This is a very good looking patch. Just a few comments:

• Please put the title of the document that the user is about to send in the title. Eg "Send Cool Doc to..."
• Please consider the empty state (no friends). You could display an empty view, like is used in the journal
• Maybe list everybody (not just friends), but put friends first
• Maybe put a search bar at the top of the popup, so that I can search for a friend I want. If I press enter, it should select the top friend.
• The dialog still stays on top even after I launch another activity. Maybe it should only be on top when I am in the journal
• Shouldn't the close button and the send button swap places?
• "Send to" in the menu could become "Send to..."
• Maybe clicking anywhere on a row should toggle it's checkbox
• The toolbuttons ("Send" "Close") don't have the roll over palettes (the type of ones that say "Send" or "Close")

[i5o]

ping..?

Also, I'm not able to merge, please update the code @AbrahmAB

[quozl]

Rebasing to resolve the conflicts doesn't look hard. Two new files, and the rest of the changes are straightforward. Then respond to @samdroid-apps comments above.

[quozl]

Off-topic comment hidden. Next action is to rebase the commits.