Feature - Add mentions in Sparks

[A-AllaaEddine]

Overview:

Mention someone in your posts (sparks) using @.

Expected Behavior:

using @ should open a list of friends (or potentially every member) with character filtering to let the user mention another member.

[danoely1979]

This is a great idea Allaa. There is a mention function when posting a comment, but its pretty rubbish and needs to be way better. So I like this idea, especially if it weights your friends on the listing is users to mention first. Also, I think it should weight the author of a post or project on the users mention list

[A-AllaaEddine]

Sure, I'll work on that.