Version 0.2-0 of lmctfy.

Major changes:
- Lock hierarchy removed, lmctfy is moving to a model where
  synchronization is external to lmctfy. Only modifying operations
  (create, update, destroy, killall, pause, resume) must be synchronized
  so they don't occur simultaneously. All other operations are safe to
  use at any time.
- CPU isolation no longer depends on the presence of the cpuset
  hierarchy. Available isolation deteriorates gracefully in this case.
- Exec() method added to the C++ library. This execs the specified
  command in the container.
- CLI now uses Exec() when running a command in the foreground.
- Spec() method added to the C++ library and spec command added to the
  CLI. This returns the ContainerSpec associated with a container.
- Misc. improvements, refactorings, and bugfixes.