* Initial scheduler commit
* global scheduler
* add global scheduler
* Implement global scheduler skeleton.
* Formatting.
* Allow local scheduler to be started without a connection to redis so that we can test it without a global scheduler.
* Fail if there are no local schedulers when the global scheduler receives a task.
* Initialize uninitialized value and formatting fix.
* Generalize local scheduler table to db client table.
* Remove code duplication in local scheduler and add flag for whether a task came from the global scheduler or not.
* Queue task specs in the local scheduler instead of tasks.
* Simple global scheduler tests, including valgrind.
* Factor out functions for starting processes.
* Fixes.
* Set logging levels in Makefile using -DRAY_COMMON_LOG_LEVEL=level
* Lower level of some LOG_ERROR messages, log the name of the table operation on failure
* Address rest of Robert's comments
* Fix spurious log message
* Merge task table and task log
* Fix test in db tests
* Address Robert's comments and some better error checking
* Add a LOG_FATAL that exits the program
* Put infrastructure in place to compute task IDs and object IDs.
* Fix version number for common library.
* Compute task IDs and object IDs deterministically.
* Address Stephanie's comments.
* Update task documentation.
* Fix formatting.
* Add more tests and checks.
* Fix formatting.
* Enable DCHECKs and change CHECKs to DCHECKs.
