Logging: Implement additional logging to rotated set of files.

* All logging duplicated into %TEMP%/{appname}/{logger_name}.log
* These are handled by the RotatingFileHandler, currently set to 1MiB
  per file and 10 backup files.
* Do *NOT* setLevel() on the handlers, as we want to control the level
  up at the logger instead.  This would have caused the CL and GUI
  selection of loglevel to NOT have any effect (hidden by default having
  been DEBUG).
* EDMarketConnector.py now INFO logs its startup and exit.

EDMCLogging.py

@@ -11,10 +11,13 @@ strings.
 from sys import _getframe as getframe
 import inspect
 import logging
+import logging.handlers
 import pathlib
+import tempfile
+from os import mkdir
 from typing import Tuple
 
-from config import config
+from config import config, appname
 
 # TODO: Tests:
 #
@@ -69,8 +72,9 @@ class Logger:
         self.logger_filter = EDMCContextFilter()
         self.logger.addFilter(self.logger_filter)
 
+        ## Our basic channel handling stdout
         self.logger_channel = logging.StreamHandler()
-        self.logger_channel.setLevel(loglevel)
+        # Do *NOT* set here, want logger's level to work: self.logger_channel.setLevel(loglevel)
 
         self.logger_formatter = logging.Formatter('%(asctime)s - %(levelname)s - %(module)s.%(qualname)s:%(lineno)d: %(message)s')  # noqa: E501
         self.logger_formatter.default_time_format = '%Y-%m-%d %H:%M:%S'
@@ -79,6 +83,24 @@ class Logger:
         self.logger_channel.setFormatter(self.logger_formatter)
         self.logger.addHandler(self.logger_channel)
 
+        ## Rotating Handler in sub-directory
+        ## We want the files in %TEMP%\{appname}\ as {logger_name}.log and rotated versions
+        ## This is {logger_name} so that EDMC.py logs to a different file.
+        logfile_rotating = pathlib.Path(tempfile.gettempdir())
+        logfile_rotating = logfile_rotating / f'{appname}'
+        try:
+            mkdir(logfile_rotating)
+        except FileExistsError:
+            pass
+        logfile_rotating = logfile_rotating / f'{logger_name}.log'
+
+        _MAXBYTES = 1024 * 1024  # 1MiB
+        _BACKUPS = 10
+        self.logger_channel_rotating = logging.handlers.RotatingFileHandler(logfile_rotating, mode='a', maxBytes=_MAXBYTES, backupCount=_BACKUPS, encoding='utf-8', delay=False)
+        # Do *NOT* set here, want logger's level to work: self.logger_channel_rotating.setLevel(loglevel)
+        self.logger_channel_rotating.setFormatter(self.logger_formatter)
+        self.logger.addHandler(self.logger_channel_rotating)
+
     def get_logger(self) -> logging.Logger:
         """
         Obtain the self.logger of the class instance.

EDMarketConnector.py

@@ -1036,6 +1036,7 @@ if __name__ == "__main__":
     if not loglevel:
         loglevel = logging.INFO
     logger.setLevel(loglevel)
+    logger.info('Startup')
 
     # TODO: unittests in place of these
     # logger.debug('Test from __main__')
@@ -1083,3 +1084,5 @@ if __name__ == "__main__":
 
     root.after(0, messagebox_not_py3)
     root.mainloop()
+
+    logger.info('Exiting')