Added handling of requests with non-existant dashboards and widgets
Moved around comments in server.render()
Made changes to handle empty results from graphite; fixed the resulting broken tests; wrote a new test for server.get_result_datapoints()
Refactored the server.get_result_datapoints() tests
Removed unnecessary the lines in server.aggregate_results_for_lvalue() doing padding of datapoints with too small a length. These lines proved to be unneccessary, as the existing code already takes such edge cases into account
Refactored the server.render() tests
Wrote tests for server.render() for cases where partial results are obtained from graphite; Handled the edge case where lvalue widgets have completely empty results.
Made changes based on jerith's review
Merge branch 'feature/issue-18-fix-problems-found-from-first-deployment' into develop