Added method ReportObject

* The ReportObject method is used to get the current ContactTrace
  object when creating a report. It is exported and can be called from
  a Sweave report template.

* Solved the NOTE from CRAN results. Now an environment is added to
  the package:EpiContactTrace environemt instead of the global
  environtment. The added environment is used by ReportObject to
  return the current ContactTrace object.
Updated Animate documentation
Updated version to 0.8.4