Check for resources in split packages

[mipastgt]

If resources of a module are placed in a top-level folder which can be interpreted as a valid java package name, then this will result in a split package error if a second module contains the same folder and both modules are used together in one project. A typical example of such a case is when you place icons that you use throughout your code into a top-level folder icons. To avoid this problem I always use a name like app-icons for such a folder because that is not a valid java package name and so does not pose a problem. The most annoying aspect is that you will only notice this bug in a module when you use a second one with the same problem. It would be nice to have a checker which can explicitly examine modules for potential problems of this kind.