Update to NRefactory 5a69aa83406d43f28db97b23d2a43a480d31f282

Changes:
5a69aa8 Add back CSharpOutputVisitor.ConvertString().
72e152d Remove the upcast in InheritanceHelper.GetBaseMembers()
137027c Suppress OptionalParameterHierarchyMismatchIssue in explicit interface implementations.
baa1464 Fixed bug in CreateEnumValue/improved type guessing.
4022d4f Merge pull request #366 from ljmeijer/script-insertafter-improvements
91fee88 fix unintended whitespace changes
f9ee154 add support for using InsertAfter() on the left parenthesis of a methoddeclaration
3d46a4a Implement support for Script.InsertAfter() to work after ParameterDeclarations
2697641 Merge pull request #365 from mono-soc-2013/MateY-IndentEngine
3f4fa3c TestComplexIfElseElsePlacement v2.
4f31fc5 TestComplexIfElseElsePlacement.
cc2a30a Added some failing formatting tests.
2f652d6 Fixed text paste bug.
35931be Fixed completion bug.
8c56bf6 Fixed bug in 'ConvertToAutoPropertyIssue'.
bc5a68b Fixed bug in RemoveBackingStoreAction
8e5f884 Found better fix for the problem.
8ca5b14 Revert "Fixed text paste bug."
132fb46 Fixed text paste bug.
b39f2cb Fixed some issue descriptions.
1c10a1c Removed duplicate code issue
59d9209 Added support for de indent anonymous method bodies. VS.NET does that with their default formatting settings - I guess it's an allman style thing. Maybe a new option should be introduced for that ?
526223b Added some parameter checks.
6509e76 Improved #region formatting.
9644e59 Merge pull request #360 from luiscubal/fix-auto-async-no-parameters
ea75bac Fixed string literal paste strategy encode/decode.
467dd74 Fixed bug in string encoding.
2044ea3 Fixed indentation bug.
50733f5 Updated mcs/fixed parser bug.
ecb2435 Fixed some failing tests.
1b63260 Fixed some issues in 'FunctionNeverReturnsIssue'.
e25edd6 Improved text paste engine.
b62c887 Fixed 'ConvertClosureToMethodGroupIssue' issue.
354d618 Improved 'FormatStringHelper' recognition.
b4cde42 Fixed AutoAsyncTests on Windows.
a96c2d0 Fixed bug in 'RedundantAssignmentIssue'.
8e52920 AutoAsyncIssue now handles parameter-less Tasks better. Auto-async issue still not fully working on Windows.
0f48a97 Investigating auto-async issue failing on Windows. Issue turned out to be related to Tasks with no parameters. Added a new unit test showing the same problem on Linux.
ceeee95 Fixed RemoveBackingStoreAction
f8ca2fe Fixed bug in ConvertToAutoPropertyIssue
68ad5a4 Fixed bug in implement abstract/interface members.
5323f0f Fixed failing unit test.
Adjust CSharpBinding to NRefactory changes.