GPL copyright statements

in order to be protected under the GPL, we need to add a copyright statement to the top of every source file in our project. 
I've added three files to docs. 
copyright.txt is our general copyright statement, 
copyrightJava.txt is a version of the copyright statement formatted into a Java-style comment,
and copyrightXML.txt is a version of the copyright statement formatted into an XML-style comment.

I plan on adding these to the top of every existing file using sed, but it's up to you guys to add a copyright statement to the top of all files created after these are put into place.

Let me know if there are any changes that you'd like me to make before they're added to the top of every file because it could be a pain to update them.