CHANGES IN VERSION 1.14.1
-----------------------
  o MS_keggNetwork returns interaction subtype (e.g. activation) instead of type (e.g. PPrel). Thank you Shilpa Harshan for noticing this!


CHANGES IN VERSION 1.7.12
-----------------------
  o MetaboSignal integrates KEGG metabolic and signaling networks with regulatory interactions reported in OmniPath and TRRUST.
  o New functions: "MS2_ppiNetwork( )" and "MS2_mergeNetworks( )".


CHANGES IN VERSION 1.7.8
-----------------------
  o MetaboSignal includes a new function: "MS_getPathIds()" which allows retrieving the identifiers (IDs)
  of all metabolic and signaling KEGG pathways of a given organism. 
  o "MS_keggNetwork()" can now transform KEGG IDs into Entrez gene IDs (use expand_genes = TRUE, 
  convert_entrez = TRUE).
  o "MS_filterNetwork()" has been renamed as "MS_topologyFilter". 

CHANGES IN VERSION 1.7.2
-----------------------
  o Major changes in function names:
  	o "MetaboSignal_matrix()" renamed as "MS_keggNetwork"
  	o "MetaboSignal_distances()" renamed as "MS_distances"
  	o "MetaboSignal_NetworkCytoscape()" renamed as "MS_shortestPathsNetwork"
  	o "MS_ToCytoscape()” renamed as "MS_exportCytoscape"
  	o "MS_ChangeNames()" renamed as "MS_changeNames"
  	o "MS_FilterNetwork()" renamed as "MS_filterNetwork"
  	o "MS_FindKEGG()" renamed as "MS_keggFinder"
  	o "MS_GetKEGG_GeneID" renamed as "MS_convertGene"
  	o "MS_NodeBW()" renamed as "MS_nodeBW"
  	o "MS_ReplaceNode()" renamed as "MS_replaceNode"
  	o "MS_RemoveNode()" renamed as "MS_removeNode"
  	o "MS_FindMappedNodes()" renamed as "MS_findMappedNodes"

  o New functions:
  	o "MS_tissueFilter()": allows filtering a network based on tissue expression data.

  o Functions removed:
  	o "MS_interactionType()": interactions can be now retrieved directly from
  	MS_keggNetwork.

  o Functionality changes:
  	o "MS_keggNetwork()": output networks are now formatted as 3-column matrices,
  	where the third column indicates interaction type. Unlike, MetaboSignal_matrix,
  	“MS_keggNetwork()" does not perform network filtering by tissue expression data.
  	Tissue filtering is now done with "MS_tissueFilter()". Also, the compound nodes
  	of the networks are not only metabolites, but also drugs and glycans.

  	o "MS_distances()", "MS_shortestPathNetworks()": use network nodes (i.e. KEGG IDs) as
  	source nodes, not entrez IDs or gene symbols. However, the function "MS_convertGene()"
  	allows to easily convert entrez IDs or gene symbols into KEGG IDs.

CHANGES IN VERSION 1.7.1
-----------------------
  o Significant improvements in the tissue-filtering option from "MetaboSignal_matrix()".
  o Cytoscape .txt files are now exported with a header.

CHANGES IN VERSION 1.1.6
-----------------------
  o MetaboSignal includes a new function: "MS_interactionType()". This function
  allows getting the interaction subtype between signaling nodes. The output
  matrix generated by this function can be used for "MetaboSignal_NetworkCytoscape()"
  and also for "MS_GetShortestpaths()".

  o "MS_GetShortestpaths()" has been modified and now the output shortest path(s)
  can be represented as a network-table (i.e. 2-column matrix).