Refactorating World: putting GUI in a separated module
Cleaning the code and removing comments
Refactorating World: putting Colors interface in GUI's package
Refactorating World: putting Robot's actions in a separated module
Cleaning the code and removing comments
Removing debug message
Passing control funtion to Action class and removing comments in World
Adding little comments
Fixing and adding javadoc for package robot
Fixing and adding javadoc for package operation
Fixing and adding javadoc for package exception
Changing build.xml to generate javadoc with package-level info