replace PIL with Pillow

Pillow is a fork of PIL, with newer features and more (pip) packaging friendly.
Update CMakeLists.txt
Peforms a 'clean' before CMake generate files
Update CMakeLists.txt
build.sh switched to use cmake

Per Issue #677
Merge pull request #681 from subutai/buildsh_changes

build.sh switched to use cmake
Merge pull request #670 from breznak/PIL_to_Pillow

replace PIL with Pillow
Added cmake check for $NTA == $NUPIC.
Deletion of old build system

Deletion of old build system (scripts at root folder will be removed
later)
Removed unecesary macro and inlined the logic.
Merge pull request #687 from DavidRagazzi/master

Deletion of old build system
Merge pull request #685 from numenta/nta-nupic-env-check

Added cmake check for $NTA == $NUPIC.
Spatial pooler pylint update.
remove (Grok specific) support files from Nupic
Merge pull request #694 from breznak/move_from_nupic

remove (Grok specific) support files from Nupic, fix Issue #330
Merge branch 'master' of github.com:numenta/nupic
Update README.md

build_system is not included with the repo so it needs to be created.
Merge pull request #695 from iandanforth/patch-3

Update README.md
Using new logo icon in README.

Also rearranged the title.
Merge pull request #696 from rhyolight/update-readme-logo

Using new logo icon in README.