Add basic issue tracking to DiffComments and ScreenshotComments

Review Request #1718 — Created July 23, 2010 and submitted — Latest diff uploaded


Review Board


The patch does the following:
-Adds an issue_opened and issue_status field in both Comment (for Diffs) and ScreenshotComment.
-Adds a BaseComment resource for DiffComment and ScreenshotComment resources to inherit from, which allows for changing Issue status
-Adds a checkbox to the comment dialog to open an issue
-Adds UI for displaying (and for review request submitters, manipulating) Issue statuses.
Added some WebAPI tests to check issue_opened/status logic.  All tests pass.