Use `System.Timeout` instead of `eager-sockets`.
Use counter for maximum wait queue length.
Revert "Use `System.Timeout` instead of `eager-sockets`."

This reverts commit 0719a798a8267cd3ced32a697882481e366c4d30.

Conflicts:
	src/Database/CQL/IO/Types.hs
Make `maxWaitQueue` setting optional.
Move `Settings` into its own module.