libev does not have a standalone Windows build, which means that using it to support Mesos on Windows would require direct integration into our build system and, perhaps, our code path.
For this reason, we need to use libevent, but this is also a big decision, as the libevent support is still provisional. So, a good solution will involve:
- Failing Windows builds if they don't pass in `-DENABLE_LIBEVENT` to opt in to libevent
- During build failure, informing them that libevent is a much less-exercised code path
- Writing logic to configure/build/install libevent locally