added setup.py to install script into system path

 - removed .py extension from script name
 - set snakefood call to only include internal libraries to speed up
   dependency checking
Merge branch 'master' into develop
added option for global vs. local dependency tracking
the .py extention in the script name is optional.
bumped version number
Merge branch 'develop'
  - merging new features of v0.13 back to master