[Build] Updated autogen.sh to a CMake-compliant version.
[Build] Updated autogen.sh to a CMake-compliant version.

airsim/airinv,airsim/airinv,airsim/airinv,airsim/airinv,airsim/airinv,airsim/airinv,airsim/airinv,airsim/airinv,airsim/airinv