By moving the stub implementation to rm_session_client.cc, we can use
the generic base/include/rm_session/client.h for base-linux and
base-nova and merely use platform-specific implementations.
Issue #1832
This patch establishes a common organization of header files
internal to the base framework. The internal headers are located at
'<repository>/src/include/base/internal/'. This structure has been
choosen to make the nature of those headers immediately clear when
included:
#include <base/internal/lock_helper.h>
Issue #1832
