* 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
* Fix socket bind collisions in manager_tests
* bind manager sockets before connecting to the store
* fix memory leak in tests
* fix valgrind early process termination
* fix bind/listen/subscribe race condition
* fix photon
* fix other tests
* make it that all of common is tested
* fix clang-format
* fix
* Ion and Philipp's table retries
* Refactor the retry struct:
- Rename it from retry_struct to retry_info
- Retry information contains the failure callback, not the retry callback
- All functions take in retry information as an arg instead of its expanded fields
* Rename cb -> callback
* Remove prints
* Fix compiler warnings
* Change some CHECKs to greatest ASSERTs
* Key outstanding callbacks hash table with timer ID instead of callback data pointer
* Use the new retry API for table commands
* Memory cleanup in plasma unit tests
* fix Robert's comments
* add valgrind for common
