replace PIL with Pillow

Pillow is a fork of PIL, with newer features and more (pip) packaging friendly.
Merge pull request #670 from breznak/PIL_to_Pillow

replace PIL with Pillow
Deletion of old build system

Deletion of old build system (scripts at root folder will be removed
later)
Merge pull request #687 from DavidRagazzi/master

Deletion of old build system
Merge branch 'master' of github.com:numenta/nupic