DOCS: add code review user manual.
commit: fixed to use 404 if it doesn't exist
fixed to use try-finally
commit: fixed to use if
Markdown: set preview block width to percents
Merge pull request #260 from whiteship/yobi refs/heads/commit/notfound
Merge pull request #245 from changsung/yobi refs/heads/userManual-codeReview
Merge pull request #263 from laziel/yobi refs/heads/yobi-499
pullrequet: fixed a bug when restoring branch
history: removed unused code
Merge pull request #264 from whiteship/yobi refs/heads/pull/branch-restore
Merge pull request #266 from whiteship/yobi refs/heads/history/merged-commit-message
history: fixed compile error
Merge pull request #267 from whiteship/yobi refs/heads/history/merged-commit-message
test: use file.encoding option for test jvm
Merge pull request #268 from kjkmadness/yobi refs/heads/bugfix/test
watch: Remove unused null-check.

If the resource is null, play always response with 400 Bad Request.
pullrequest: fixed the commit id link
Merge pull request #269 from npcode/yobi refs/heads/fix/remove-unused-null-check
Merge pull request #272 from whiteship/yobi refs/heads/pull/changes-commit-id