New UI for discussions

the button is appears only as "...". "More" appears only on mouseover. You can check out the UI on Greg's sandbox here: http://gwprice.m.sandbox.edx.org
I think it's important to indicate that this is an icon as there is a learned association between it and the concept "more". "Pin" on the other hand has both a text label and an image so there is the likelihood of immediate recognition...