Allow users to download a review request as a PDF and XML(WIP) document.
For the sample mock documents, refer to the review request https://reviews.reviewboard.org/r/6413/
TODO:

Finish XML.
NOTE:

this depends on:

1. https://reviews.reviewboard.org/r/6633/

2. https://reviews.reviewboard.org/r/6620/

Issue Summary Section

1. No Issues

2. Open Issues

3. Open & Resolved Issues

4. Open & Dropped Issues

5. Dropped Issues

File Summary Section

1. No Files

2. Files only uploaded

3. Files uploaded and downloaded
Review Summary Section

1. Added/Removed content to description and testing done (Displayed as +/-)

3. Review with only body_top

4. Review with Comment and no replies

5. Review with Comment and replies

6. Issue Opened (Review displays "Issue Opened by 'name' ('status')")

7. Issue Resolved

8. Issue Dropped

9. Added Files (Specified in the ChangeDescription as a bulleted list)

10. Removed Files (Specified in the ChangeDescription as a bulleted list)

11. Comment of File Attachment

12. Added/Removed Bugs Closd (Displayed as  +/-)

13. Added/Removed Branch (Displayed as  +/-)

14. Added/Removed Target People (Displayed as bulleted list)

15. Modifed Summary (Displayed as +/-)