Update Part II: HelloWorld.md

removed jsplitpane due to it being moved
Update Part VIII: Classes.md
Added social buttons
Update Part I: MyFirstWindow.md
Update Part IV: Temperature.md
Update Part II: Printing.md
Update Part II: Printing.md
Update Part II: Printing.md
Update Part II: Printing.md
Update Part II: Printing.md
Update Part II: Printing.md
Merge pull request #43 from BillsJ/patch-4

Update Part II: HelloWorld.md
Better mobile compatibility
Made faster by compressing CSS
GitHub ribbon uses sans-serif font
Update README.md
Update README.md
Update README.md
Update package.json
Update Part VII: Exercises.md