[FIX]Rename icons to match real options. 0 needs to be the question mark on grey, which is not counted for the averages. All the others renamed also to one lower value, to match current value ranges. Values from ranges also adapted to have them more equally distant from both ends in each case. Addresses half of the issues reported in bug5257.

git-svn-id: file:///var/local/code.tiki.org/tikisvn/branches/13.x@51550 b456876b-0849-0410-b77d-98878d47e9d5