log: route task/component status output through logging, not print()

AttributeChange (the common base of every ATask and component ABC) now
sets self.log = logging.getLogger(type(self).__name__), so components
no longer need to hand-type their own name into each message. Wired
logging.basicConfig() in server/brewpi.py with a bare "%(name)s:
%(message)s" formatter - Tee (see prior commit) still supplies the
"<date>T<time>:" prefix, so lines read "<date>T<time>:<component>:
<message>" without double-stamping, and third-party loggers
(websockets, asyncio) now get the same formatting for free.

Converted the print() call sites that were standing in for this in
tasks/ and components/ (leaving __main__ demo blocks and explicit
debug-dump helpers alone).

components/actor/stirrerpololu1376.py

@@ -46,7 +46,7 @@ class StirrerPololu1376(AStirrer):
 		if not self.connected:
 			return
 		try:
-			print("activate {}".format(enable))
+			self.log.debug("activate {}".format(enable))
 			if enable:
 				self.drv.go()
 			else:
@@ -58,7 +58,7 @@ class StirrerPololu1376(AStirrer):
 			# loop (with self.device.open(): activate(True)/(False)) and
 			# from a client's Connect/Disconnect command, neither of which
 			# expect activate() itself to ever raise.
-			print(f"StirrerPololu1376: comm error in activate({enable}): {e}")
+			self.log.error(f"comm error in activate({enable}): {e}")
 			self.disconnect()
 
 	def _on_set_speed(self, speed):
@@ -66,9 +66,9 @@ class StirrerPololu1376(AStirrer):
 			return
 		try:
 			self.drv.motor_forward(speed)
-			print("Set speed to {} %".format(speed))
+			self.log.debug("Set speed to {} %".format(speed))
 		except Exception as e:
-			print(f"StirrerPololu1376: comm error in _on_set_speed: {e}")
+			self.log.error(f"comm error in _on_set_speed: {e}")
 			self.disconnect()
 
 	def _on_process(self):
@@ -77,12 +77,12 @@ class StirrerPololu1376(AStirrer):
 		try:
 			errors = self.drv.get_status_errors()
 			if errors:
-				print(f"StirrerPololu1376: motor controller reports errors: {errors!r}")
+				self.log.warning(f"motor controller reports errors: {errors!r}")
 				if StatusError.SAFE_START_VIOLATION in errors:
-					print("Recover after safe start violation!")
+					self.log.warning("Recover after safe start violation!")
 					self.drv.go()
 		except Exception as e:
-			print(f"StirrerPololu1376: comm error in _on_process: {e}")
+			self.log.error(f"comm error in _on_process: {e}")
 			self.disconnect()