Setup an ABI compliance tracker before releasing v1.0

[coryan]

The ABI will change dramatically during the initial development, but should be fixed after v1.0.0 and this should be enforced using a compliance tool such as:

https://github.com/lvc/abi-compliance-checker

[coryan]

Notice that ABI compliance trackers depend on having shared libraries, which are impossible to produce right now because Abseil only produces static libraries.

[coryan]

This was fixed by #644.