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).

tasks/stirrer.py

@@ -88,11 +88,11 @@ class StirrerTask(ATask):
 						try:
 							self.device.process()
 						except Exception as e:
-							print(f"StirrerTask: comm error, marking disconnected: {e}")
+							self.log.error(f"comm error, marking disconnected: {e}")
 							self.disconnect()
 						await asyncio.sleep(self.interval)
 			except Exception as e:
-				print(f"StirrerTask: unexpected error, recovering: {e}")
+				self.log.error(f"unexpected error, recovering: {e}")
 				try:
 					self.disconnect()
 				except Exception: