Merge pull request #5 from BillsJ/master

small things - merging, spelling of arithmetic and adding more images
Update Part I: Introduction and contents.md
Update and rename Part I: GUIpplication.md to Part I: MyFirstWindow.md
Update index.html
Create Part V: The Border Layout.md
Update Part V: The Border Layout.md
Create Addendum I: History of Java.md
Update Part I: MyFirstWindow.md