Added client-wide state hash

Author: jath03

openrgb/orgb.py

@@ -643,3 +643,11 @@ def ee_devices(self):
         control mode.  These devices are suitable to use with an effects engine.
         '''
         return [dev for dev in self.devices for mode in dev.modes if mode.name.lower() == 'direct']
+
+    @property
+    def state_hash(self):
+        '''
+        A hash of the current state of all devices, for use in tracking
+        changes.  Note that python's hash function is not process-stable.
+        '''
+        return hash("".join(str(dev.state_hash) for dev in self.devices))