Add ModuleItem#getGenericType() method

This method lets you query the type of a module input or output,
*including* generics, which is useful for more precise matching and
conversion of objects to and from that type.
AbstractModuleItem: expose getDelegateClass() method

This method is useful for obtaining the actual Class object of the
module item, loading it if necessary. We could recapitulate the logic
everywhere else (it is only one line of code), but it would be longer
and uglier than simply calling getDelegateClass() from subclasses.
Resolve CommandModuleItem types more precisely

This updates the SciJava Common dependency to 2.13.0, to take advantage
of the new getTypes(Field, Class) and getGenericType(Field, Class)
methods of ClassUtils. Thank you, gentyref!
Merge branch 'resolve-generics'

This branch improves the behavior of ModuleItem#getType() when generics
are involved. In many cases it is possible to deduce a narrower (i.e.,
more precise) type for the field, when class hierarchies are involved.

We also add a ModuleItem#getGenericType() method, so that further
reasoning about the type may be done externally, since an erased Class
may not be sufficient for certain purposes.