2009-8-4
  *make network plot can do two traits together.
2009-6-26
  *change some warning.
2009-6-24
  *add subdirectory /R/sysdata.rda file, make environment .rqtlnetwork works, so it don't need to generate r object in .GlobalEnv
2010-2-10
  *rename the package by QTLNetworkR
2010-5-31
  *Multiple traits for QE
2010-6-10
  *Merge QTLs with crossed confidence interval
2010-6-18
  *Use text to distinguish different environments