add size submenu to images+discussion

I like it.  And I had just been thinking we might want to do some cardtype specific menus (eg for Cardtype cards).  Kinda thinking top level menu might be "image", but we can play with that. 

this is also somewhat related to the refresh menu we just lost.

I think I'd put up a pretty strong vote against "image" if it only had one item in it - "size".

  --John Abbe.....2013-03-22 08:52:48 +0000

I was thinking it might also offer access to other link forms:

1. fast (default): http://wagn.org/files/bruce_logo-large-122798.png

2.download: (attachment disposition) (eg http://wagn.org/files/bruce_logo-large-122798.file)

3. latest: (always gives most recent): http://wagn.org/bruce_logo.png?size=large

  --Ethan McCutchen.....2013-03-27 16:59:13 +0000

3. Latest or most recent what?

2. I see some value for this, but not enough if it's the item that creates the need for an extra submenu.

  --John Abbe.....2013-03-27 19:28:11 +0000

3. revision. (eg, upload new image and that url gives you the current one, whereas other is revision-specific)

  --Ethan McCutchen.....2013-03-27 20:34:49 +0000

Got it. And all of this in advanced, or...?

  --John Abbe.....2013-03-27 21:15:02 +0000