Improve error message for transform initializers

Before dispatching adding check that the input images match the type
and dimension as required. Also the transform is checked that the
dimension matches.

Change-Id: I9ad9ce09eda5afc2d43c8feb17180c106799e98c
Merge branch 'master' into SIMPLEITK-563_WrapCenteredVersorTransformInitializer

Change-Id: I3363d24b41cec64f145de65f8ffc165429b3cde9
Adding explicit constructor from base transform to vesor

Change-Id: I5d7fb1b55e697e45ea6d4307dbeea0295c43e105
Moving vector testing facilities to SimpleITKTestHarness

Change-Id: Ida1c29135c24c5262f09bdf16bf530ed7238e3d1
Merge topic 'SIMPLEITK-563_WrapCenteredVersorTransformInitializer' into next

036ab30e Moving vector testing facilities to SimpleITKTestHarness
29458f67 Adding explicit constructor from base transform to vesor
f3e70783 Merge branch 'master' into SIMPLEITK-563_WrapCenteredVersorTransformInitializer
f19673a9 Improve error message for transform initializers