enhance comment page ui prototype

with:
1. some keywords changed. e.g. note -> draft, display archived courses -> include archived courses
2. wider comment box
3. add a tab for drafts in the pagination
4. display edit bar on hover
5. group by photo for student records comments
6. add styles for visibility options. e.g. to XXX --> From you to XXX, From Instructor3 to XXX

not impl yet:
1. stu photo in comment box's auto-complete suggestion
2. stu photo in comments
minor tweak in comment page

with:
1. update feedback response comment style
2. remove drafts in mockup (it'll be similar to 'Comments about students')
update comment edit page

with
1. update keywords. e.g. note -> draft
2. add stub for instructions...
Merge remote-tracking branch 'origin/master' into Issue2151