Using relative links in readme

to avoid confusion in different branches or forks
Explicitly pointed out minimal scopes
Use CSS transition for help popup, clean up code, fix CSS syntax causing Safari to choke
Fix bug commit->code still show sidebar
Split work into chunks to improve UI responsiveness on large repos; update sort to match GitHub's algorithm
Merge pull request #88 from bayandin/specific-scopes

Explicitly pointed out minimal scopes (for github token) in readme
Update read me
Update #98