Global scheduler skeleton (#45)

* 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.

lib/python/photon/__init__.py

@@ -1 +1 @@
-from libphoton import *
+from photon import *

lib/python/photon/photon/__init__.py

@@ -0,0 +1,2 @@
+from libphoton import *
+from photon_services import *