Update README.md

newImage.sh tested on Ubuntu 12.04
Merge pull request #19 from hhzl/master

Update README.md
Fixes and enhancements fro Andres, Casey, Ken, Juan and Squeak
Meerge branch 'master' of github.com:Cuis-Smalltalk/Cuis-Smalltalk-Dev
popo:x
merged 12/14/13 upstream