Deal with limitations for generic types

[oscarlvp]

In some scenarios, where the result of a expression is a generic type with a concrete parameter type, say List<String>, Spoon would report the type as List<Object>. This may lead to the creation of code that can not be compiled.
Right now, all expressions with such types are not included in the analysis.
Deal with these limitations to include cases in which Spoon correctly guessed the parameter type.