TNL-932: Add styling to Notes page.

TNL-932
@tymofij, @jmclaus, @clrux please review.

**sandbox:** http://tymofij.m.sandbox.edx.org/courses/edX/DemoX/Demo_Course/edxnotes/
yes, and question was about the need for retrieval of recently viewed component.

I see now that it is used for displaying a link when no notes are present, thanks.