Make --lock default to True. Add --nolock to provide lockless functionality when needed
Make nolock default when using luigi.build
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
Add String column types in the history db a length - as required by mysql dialect
Merge pull request #319 from rantav/history_db_mysql_fixes

MySQL fixes to the history db
Renames flag to --no-lock and adds warning when --lock is used
Makes getpcmd and thereby process locking MacOSX-compatible
- don't disable existing loggers when logging.config.fileConfig is
  called by luigi
Merge pull request #321 from JonNelson/no_disable_existing_loggers

- don't disable existing loggers when logging.config.fileConfig is called by luigi
Merge pull request #320 from daleroberts/daleroberts/allow_worker_subclassing

Minor refactoring of Worker to allow easier subclassing
Add ON DUPLICATE KEY UPDATE clause to the MySQL target touch method. This will prevent errors and do a no-op in case the update marker already exists
Merge pull request #322 from rantav/mysql-improvements

Add ON DUPLICATE KEY UPDATE clause to the MySQL target touch method.
include worker id and host in log output

Makes log output more usable for troubleshooting when somewhere a worker process is hung. The "is currently run by worker-RANDOM_NUMBER" error message will now include the host, and logs on that host will let associate it with the pid.
Adding my local Vagrant bits to gitignore
Adding a target and external task for EMR output stored on S3
Fixed bugs in hive.py
Check for missing files in distributed cache setup
Merge pull request #327 from a1k0n/dcachecheck

Check for missing files in distributed cache setup
PyPI now using RST docs + uploaded new 1.0.14 version
update MANIFEST.in for new README.rst