R1:2a894438ae33

Add a 'description' field to Phriction

Summary:
Add a new column to PhrictionContent called 'comment' or 'description' or
something
Add an optional field to the Phriction document editing interface that
allows you to add a comment

Test Plan:
Run the sql patch to modify phriction_content table
Create a new wiki page in Phriction
Type in words in description field and save the page
Visit this page and click "Edit Page" button
The content in the desciption…