Add tool tips to checkboxes in edit item screen

This item has been included in the 1.1.0-rc1 and rolled to UCD staging in preparation for production release.

not a FULL pass...because Fernandy and I both think the scale extra credit
information is hard to understand...and we KNOW what it's supposed to do.

Closing since this is a QA pass.

I've created to address the length of the display.

QA ENVIRONMENT -
vista enterprise, firefox, ie7
smartsite-test sakai_2-5-x-test-078 - Sakai 2.5.x-R57934 gb2-1.1.0-b4 - Server sakaitest2

QA SUMMARY -
followed test plan above on no categories, categories and weighted category sites ( so I
don't miss any site type specific boxes).

• gradebook setup -
  1 - I still don't see the difference between the gradebook "display released items" and the
  item "release scores."
  if I release item scores and un-check the display released items (checked by default) box
  in gb setup, as the student I still see all the individually released item grades. so what's the difference?
  but if everyone else understands it I guess all is well.
  2 - the info for scale extra credit was not clear to me until I read it a number of times. maybe it
  will be clearer to IORs? what does Fernandy say? he says unclear, too....see comment above,
  which makes sense IF you know who Jaques Derrida is

• categories -
  categories only - all clear
  weighted cats - clear

• items -
  1 - see comment #1 above re: release scores.

QA RESULTS -
pretty much pass on -test

QA COMMENTS -
can popups display a little longer or disappear on mouse click or something?
I can't read the "scale extra credit" one before it disappears and had to do multiple scroll-
overs to get it all read.