Fix source code formatting, using Artistic Style

Artistic Style (http://astyle.sourceforge.net) is an automatic source code
formatter. The options used to format the EduMIPS64 source code are:

--indent=spaces=2 --brackets=attach --break-blocks --pad-oper
--pad-header --unpad-paren --add-brackets --convert-tabs --mode=java
Use raw JList/JComboBox, and suppress warning

Because the generic types were introduced in Java 7 and so are not compatible
with Java 6. (Thanks TravisCI for finding this).