This provides clean separation between the ORC runtime code that
implements runtime functionality and the wrapper functions that permit
this code to be called from the controller via the
ExecutorProcessControl API.
Separating the controller interface from the implementation functions
should allow clients to introduce alternative serialization schemes if
they want (e.g. JSON).
In particular, this commit adds a new orc-rt/include/orc-rt/sps-ci
directory and moves SimpleNativeMemoryMap SPS controller interface into
a new header in that directory. This commit also splits the
implementation and testing of the SPS controller interface for
SimpleNativeMemoryMap into separate files.
