- add code to ModifierCorrectionSubProcessor to call the
  UnresolvedElementsSubProcessor.getVariableProposals in the case
  where we have a reference to a non-static field of a super
  class
- add new test to QuickFixTest18

Change-Id: I35b0b97028186d32324efb6265bfc953cd7061b0
Signed-off-by: Jeff Johnston <jjohnstn@redhat.com>