0.2
- generate.pathway: remove duplicat connections between two nodes.

0.3
- Add univariate procedures

0.4
- remove function eccentricity since igraph v 6.0 has add it.
- change network visualization part with the igraph v 6.0.
- PID data has been updated to the latest version (at 2012_07_19 09:34::20).
- network can be visualized by Cytoscape web.
- add function for parallel computing

0.5
- change gene level to node level
- node level can be self-defined
- pathway level can be self-defined
- adjust the figures
- handle if core number are larger than pathways
- doc and vignette habe bee improved
- numbers of differential genes/nodes and all genes/nodes can be listed in the report
- add two vignettes
