pass path instead of scheme+host+path of parsed pagination links

thereby fixing pagination in GitHub Enterprise (while not breaking it in
regular GitHub)
also use the URI module to parse query strings
Merge branch 'master' of github.com:peter-murach/github
do not prepend path prefix if the path already starts with it
fix enterprise typo in README :neckbeard:
Merge pull request #90 from boyan/master

Enable page navigation for GitHub Enterprise