should use width=120 in many places

We should be using references to the downscaled versions of the profile picture in most places where the profile picture is displayed, for both users and groups, so that a faster delivery occurs and the browser is less demanded.

Adding the parameter width=120 whenever a profile picture is displayed appears to be the solution.

For some reasons, this is not used in the UI code of Curriki currently.
I've asked XWiki-ers why.