- add new findFieldReferencesForType() method to ExtractMethodAnalyzer
  to find field references in the inner type where selection is made
- add new logic to ExtractMethodRefactoring to recognize a move to
  an outer class where fields are referenced in inner in which case
  pass an extra parameter of the inner type and qualify any field
  references using this extra parameter
- add new test to ExtractMethodTests
- fixes #1458