Fixed the caching/retrieving of branches and leaves
Fixed the caching/retrieving of branches and leaves

Without these changes you will never get any series returned from the
assure_series method and the get_leaves method does not check if a leaf
is actually a leaf…

InfluxGraph/influxgraph,InfluxGraph/influxgraph,vimeo/graphite-influxdb,raintank/graphite-influxdb