Merge topic 'SIMPLEITK-573_AddAdditionalTransformMethods'

9336a7c4 Adding Transform::IsLinear method
09f80fad Adding missing declaration of GetInverse in PimpleTransform base
98b38a5d Adding comprehensive testing for GetInverse method
5d4447e5 Adding doxygen comment for SetInverse
501ea0b9 Adding GetInverse method to transforms
Merge branch 'master' into next

Change-Id: I49cfd354b02edb83754b3b52aab0a9212d8a5218