lukko: File locking

This package provides access to platform dependent file locking APIs:

Open file descriptor locking on Linux (Lukko.OFD)
BSD-style flock(2) locks on UNIX platforms (Lukko.FLock)
Windows locking via LockFileEx (Lukko.Windows)
No-op locking, which throws exceptions (Lukko.NoOp)
Lukko module exports the best option for the target platform with
uniform API.

After uninstalling, run this command to unregister the package from
the ghc package database:   ghc-pkg recache