Rework project's code structure

The project's code structure does not follow any "industry standard", which hinders the possibility of:

1. outside contributions to the project
2. the use of external tools designed with expectations about the code structure

Some "red flags" of the code structure are as follows:

1. Resources (DTDs, images, html pages, translation files) are mixed with source code
2. Source/class files of user-made scheduling and allocation policies are not in an appropriate place; it is better to have them in their own folder and label such folder as "Generated Sources"
3. Test source code files are outside the src folder