Changed maven jdom depedency from 2.0.4 to 2.0.3 and added junit dependency

jdom 2.0.4 not found and junit will be used to add assertions to java classes.
Corrected package and import statements now that the project is a Maven based project

also removed an unused line from eachChar.kt
Added /target/ to the .gitignore now that this is a mavan project
Added and example of a java NullPointerException and showed how kotlin can handle it with the null safe operator, the Elvis operator and the !! operator