Code review comment for lp://staging/~ted/ubuntu-app-launch/abi-compliance

Approving the CMake. Optional comments inline.

As for the ABI part -- Since Ted's gotten in-IRC comment from Seb128 and Laney, I'd prefer to see one of them here for reviewing the actual ABI test.

+1 to the Dobey/Ted comments that this is a step forward rather than a total fix.