Code Modularisation Support

[jbee]

Add something that allows to check for proper code modularisation. Instead of using modules on build level (e.g. maven) to avoid unwanted code dependencies packages in a single build module could be used as long as some tool tells us when "illegal" references are created. The DI container could help with this to some extend. While it cannot check and enforce universal class level isolation it can make sure container managed instances are not used where they should not be used. In connection with vanilla java visibility modifiers this allows to write code that is hardened against "spaghetti" code effect.