Update files using http://w3c-test.org/

Because W3C has refactored http://w3c-test.org/,
these links are not valid any more.
Just replace them with links to W3C github repos.

We still needs to check the integrated files
to reflect the latest W3C github repos.
Remove unreferenced files linking to http://w3c-test.org/
Correct test origination of Geolocation test suites

However these tests have been deprecated by
https://github.com/w3c/web-platform-tests/tree/master/geolocation-API

We need to update the test suites too.
Merge pull request #1132 from zqzhang/w3c-test.org

Check files linking to http://w3c-test.org/