ENH: Added *.remote.cmake for remote module VariationalRegistration

This version uses bd3ae2f8a37f76dc1700e7369e8edb03c31ff6dd.

Change-Id: I0dd31de20480934229efc019ef95416245286224
DOC: Improve documentation and types for SplitRequestedRegion.

Improve doxygen documentation for ImageSource::SplitRequestedRegion.

Change-Id: I5a713a04f27ae0094e46be1c628330a466778863
Merge topic 'splitter-doc'

8e27a1b6 DOC: Improve documentation and types for SplitRequestedRegion.
Merge topic 'add_remote_module_variational_registration'

26ac0952 ENH: Added *.remote.cmake for remote module VariationalRegistration