Merge pull request #775 from Kixeye/0.9.x-remotefetchfix

Check for empty result from remote node
Merge pull request #769 from macolu/fix-typeError

Fix TypeError with sum() function
Merge pull request #773 from Kixeye/0.9.x-funcdocfix

Minor documentation fix for sumSeriesWithWildcards() function (0.9.x)
Merge pull request #759 from Kixeye/0.9.x-webapp-customremoteuserbackend

Allow the use of a custom remote user backend (0.9.x)
Merge pull request #30 from graphite-project/0.9.x

Pull in Upstream Changes