CMake: Update Interrogate.cmake macro's use of COMPILE_DEFINITIONS:

- Slightly older versions of CMake default this to NOTFOUND, so test before iterating.
- Add to local definitions for building the _igate sources.
CMake: Interrogate/build nativenet, net.
CMake: Work on direct; get dcparse, dcparser, deadrec, directbase, distributed to build+Interrogate.
CMake: Update autorestart's CMakeLists to match the COMPILE_DEFINITIONS (rather than add_definitions) of the other components' CMakeLists files.