Make --lock default to True. Add --nolock to provide lockless functionality when needed
Make nolock default when using luigi.build
Renames flag to --no-lock and adds warning when --lock is used
Makes getpcmd and thereby process locking MacOSX-compatible
Adding my local Vagrant bits to gitignore
Adding a target and external task for EMR output stored on S3
Fixed bugs in hive.py
Changes to scheduler to allow for workerless task submission.
Fixed an issue introduced in 6330e9d0332e6152996292a39c42f752b9288c96

- Previous commit introduced a bug that would cause tasks not to be exposed if they changed name after creation
- Added a new unit test for this case
- Ended up removing a lot of the code introduced in the previous commit and replaced it with a much simpler mechanism
- Removed some unit tests for unregister() since I decided that method wasn't a good idea to have
Make luigid logging level configurable
Fix endlessly growing list of tasks with no stakeholders
Worker can only become a stakeholder when scheduling a task.
Allow non-FIFO task retrieval for faster scheduler performance
Allow disabling of request logging; other logging tweaks
Merge branch 'workerless-task' of github.com:Multifarious/luigi into workerless-task

Conflicts:
	luigi/scheduler.py