adds support for building the model of a program for which the classpath is incomplete

> >  			}
> > +		} catch (Exception e) {
> > +			throw new SpoonException(e);
>
> I would like to have an additional message. Why did this exception
> occur? Which task failed?
>
This is the well-known implementation pattern of transforming a checked
exception in an unchecked one (as used for instance in Spring). In this
case, e.getMessage() describes the problem.