pullrequest: updated view

* showing diff commits of closed pullreuqest
issue: fix search bug (#157)
issue: display search options (label)
Merge pull request #130 from kjkmadness/yobi refs/heads/bugfix/issue-search
Merge pull request #129 from whiteship/yobi refs/heads/pullrequest/commits
Fix an exception while getting watchers for issue.

Fix an exception while getting watchers if the author's account is
removed, by making User.getAuthor() returns anonymous if the user does
not exist.