Update Appcache Facts link

The old version is no longer maintained.
Merge pull request #47 from demands/patch-1

Update Appcache Facts link
Update README.md
Update README.md
Add options.absolutePaths.

This fixes issues with single-page applications that use pushState.
The applications may serve up `index.html` for a URI with a long
path, such as `http://mytodoapp.com/items/4`