TEST: added test for setter of the WeightedGraphPartition object
TEST: added test for setter of WeightedPartition, catch partition with missing nodes
DOC: update weightedpartition doc string
RF: changed dnodecom to node_degree_by_community for clarity
RF: changed total_weights to degree_by_community for clarity
RF: changed internal_links to degree_within_community for clarity
RF: clean up LouvainCommunityDetection docs and methods
DOC: improve metagraph docs and misc cleanup