Fix a Rest interface bug and do some misc. minor changes:
- Fix Result.fetch_details bug: pass cookies to http.get.
- Add Change.commit_url method.
- Add optional params argument to Plan.results. Mostly used to limit the number of resutls by passing in max-results.
- Add debug URL logging to Json get method.
- Update specs for changes.
Merge pull request #8 from rnadler/master

Fix a Rest interface bug and do some misc. minor changes