Changes in version 1.9.4 (2014-04-04)
  - Updated Biocarta, KEGG, NCI and Reactome data.
  - New databases: HumanCyc and Panther.

Changes in version 1.11.4 (2014-10-01)
  - Updated Biocarta, KEGG, NCI, HumanCyc, Panther and Reactome data.

Changes in version 1.13.2 (2015-04-02)
  - Pathways for multiple species: see pathwayDatabases() output.
  - Native pathway IDs.
  - Removed SPIKE database.
  - Deprecated objects: biocarta, humancyc, kegg, nci, panther, reactome.
  - Deprecated functions: runClipperMulti, runDEGraphMulti, runTopologyGSAMulti.

Changes in version 1.15.3 (2015-10-07)
  - Updated all pathway data.
  - More descriptive edge types.
  - Use the package "rappdirs" to select a directory for cached files.
