Feature/f2a/aspects on imports

[MLanghammer]

The PR introduces code to deal with the creation of multiple autosar files from multiple franca files. Note: needs to be merged after feature/aspects-on-imports

[MLanghammer]

Hi, I adressed all comments except the following:

* The test base methods contain a lot of code that is redundant with code in "AbstractFaraconConverter.xtend". Test methods should call 'AbstractFaraconConverter.convertFiles' instead as the test project is dependent on the project "org.genivi.faracon.cli" anyway. The public visibility of 'AbstractFaraconConverter.createResourceSet' and 'AbstractFaraconConverter.resolveProxiesAndCheckRemaining' indicates this issue as well.

• you are right, however, simply calling the convertFiles method would not help, as in the tests often given models are converted. This is why I decided to duplicate the calls to the methods. I guess it is possible to create a method convertModel in AbstractFaraconConverter and call this one. This would save us one or two method calls in the tests. I am not sure whether it makes sense to implement such a method for test purposes. What is your opionon?

[MLanghammer]

There should be added a comment why the additional model parameter has been added to the method 'FrancaImportCreator.createAndAddImportTo'. Otherwise it will be reactored to use the class attribute 'currentModel' directly instead. All other changes look good.

Good point - did that :)