boostrap.py improvments
boostrap.py improvments

 * relax never-download requirement: This was useful for earlier
   development to make sure we got significant requirements packaged,
   less so now.
 * print a success message at the end.
 * Create webroot directory if it doesn't exist.

victor-lin/npact,victor-lin/npact,victor-lin/npact,victor-lin/npact,NProfileAnalysisComputationalTool/npact,NProfileAnalysisComputationalTool/npact,NProfileAnalysisComputationalTool/npact,NProfileAnalysisComputationalTool/npact,NProfileAnalysisComputationalTool/npact,victor-lin/npact