OptionalParameterMismatchIssue: Added support for null default values (which previously caused null reference exceptions).
OptionalParameterValueMismatchTests: Added new test demonstrating null default values.
Merge branch 'master' of git://github.com/icsharpcode/NRefactory into luiscubal-optional-name-mismatch
OptionalParameterHierarchyMismatchIssue: Added support for null default values (which were apparently lost in a merge operation).
Added support for indexers in OptionalParameterHierarchyMismatchIssue
Merge pull request #249 from mono-soc-2013/luiscubal-optional-name-mismatch

Improved  OptionalParameterHierarchyMismatchIssue