ticket #213 - issue with deleting post analysis node and edges from and stored session and trying to reload the node (usually done with different paramters) but only the node gets added back.  When nodes and edges are deleted they are not deleted from the set of genesets and gene set similarity.  On recomputed if the edge existed in the set I didn't re-create it.  Change this to updated the gene set similarity and it get re-added.  Also fixed issues with stored old sessions missing GSEA ranking and issue with expression data coming from rank files in the edb directory.