- fix ScopeAnalyzer.isVisible method to return false if the context is an inner static class
  and the binding is a non-static field that does not belong to inner class
- fix ScopeAnalyzer.getUsedVariableNames() to use the CHECK_VISIBILITY flag
- add new test to AssistQuickFixTest

Change-Id: I763f15aaa89c6e12e2f2ed741e8c3fffc1d2fc91
Signed-off-by: Jeff Johnston <jjohnstn@redhat.com>