Makefile enabled build.

[aregtech]

Since building AREG SDK with Makefile is getting more difficult and it takes more time, the decision is done to at least temporary to disable the build with make tool. If anyone would like to continue to support build with make, please feel free to continue and integrate:

• fetching googletest to the build instead of using submodules (see issue stop using submodules #194)
• integrate automatic code generator in the build process (see issue CMake changes to generate code #175)
  In next versions only builds with cmake and msbuild (MSVC) are supported.

---

This discussion was created from the release Makefile enabled build..