* Use the new locks for schema updates
* removed schema lock from discovery
* Add the ability to wait for a lock.
Add unit tests
* Add MysqlLock
Use that for the schema updates
Wait up to 30s for other schema updates to complete.
* Switch the schema lock back to a file lock for now.
Make FileLock support indefinite locking without polling.
Add a warning to MysqlLock for scenarios where it won't work.
* Delete MysqlLock.php
* Removed MySQL lock tests
