Very minor edits to Policy section.

Mostly typos and citations.
Adds opening parapraph to Implementing Policy.
Adds Daisie Huang's speaker notes.

Adding them as comments for now. These summarize the papers in this section
(Implementing Policy).
First paragraph in Implementing Policy.
Second paragraph in Implementing Policy.
Author order change for Krintz et al.
Summarized paper 1 in Implementing Policy.
Small fixes in Implementing Policy.
Reformat to break lines in paragraph.

This is for easier readability in online interface to VCS - I thought Github
already breaks lines in text, but apparently not.
Heiland et al summary for Implementing Policy.
Merge branch 'impl-policy-1'

First set of edits for filling in the section on Implementing Policy.