fork: Save disk space using hardlink while cloning

Hardlink to files under .git/objects except .git/info/alternates while
cloning to save disk space, as git does.
add link to codeViewer for specific commitId
referring issues from a pullrequest and a commit
Fix messages
Merge pull request #119 from npcode/yobi refs/heads/feature/clone-using-hardlink
Merge pull request #126 from alecsiel/yobi refs/heads/issue-refer
Merge pull request #122 from laziel/yobi refs/heads/yobi-129
replace default project logo with new BI
add side-by-side diff with mergely.js
rename/move template files.

- beautify app.secret/app.restart page
Merge pull request #127 from laziel/yobi refs/heads/yobi-129
Merge pull request #124 from laziel/yobi refs/heads/yobi-180
add fullDiff to pullRequest diffView
Merge pull request #128 from laziel/yobi refs/heads/yobi-129
show file history (#292)
fileAsJson, findFileInfo changes

- fileAsJson returns same format whichever Git or SVN
- rename findFileInfo to getMetaDataFromPath
fix #360. encode branch URL.
add browse code button explicitly
replace .nbtn to .ybtn
add button.newIssue on messsages.ja