format uptime to day hour min
Use Markdown syntax instead of HTML.

Also touch up README.
Remove IE note; implicit in "modern browsers".

IE9+ are considered modern browsers, and although you can't run the
dashboard on Windows nothing prevents you from accessing the page using
IE.
Merge pull request #79 from commonquail/readme

Simplify readme
Merge pull request #77 from arnaudbey/master

format uptime to day hour min
removed CDN URLs; added locally