Add autotools-style Mesos distributions to the CMake build system

In the autoconf-based build system, we there is a notion of building a "distribution" of Mesos. Essentially, it is a version of Mesos that is configured for a specific platform (Ubuntu, say); so, if a consumer knows their platform, and there is a Mesos distribution, they need only run `make all` and Mesos builds. This allows the consumer to skip the configure step.

In CMake, it should be possible to do this (should be!), and we should explore making it work after we complete the MVP.