Created a new visitor for JDT ASTNodes. It allows for an execption to be
thrown and a return value.
Reimplemented JDTTypes.getType methods as a visitor
ExpressionResolver returns the Type of an Expression. I'm using my old
Reflection2 library to handle the method resolution. I don't want to
reimplement the boxing/unboxing and varargs parts.
Added hashCode, equals, and toString to NestedClass