Update suppressed warnings for newer versions.

Continue to suppress newer version of the CSharp version warning.

Suppress the following warning from gcc 4.7.2:
SimpleITK-Release/ITK-prefix/include/ITK-4.5/itkImageRegionConstIteratorWithIndex.hxx:37:5:
warning: assuming signed overflow does not occur when assuming that (X
+ c)

Change-Id: I919ee4bb2697c5cb6b1826010d4d3cdb3fb61e4d
Merge topic 'SIMPLEITK-492_FixWarnings' into next

5ac54209 Update suppressed warnings for newer versions.