migrate to tox

this also requires to move default configuration files to share/ahriman.
Thus the following features have been added
* default configuration is not stored in /usr/share/ahriman/settings
* package installed via PKGBUILD now copies files from /usr
* configuration class now fallbacks to default in /usr

package/share/ahriman/settings/ahriman.ini.d/logging.ini

@@ -0,0 +1,74 @@
+[loggers]
+keys = root,build_details,http,stderr,boto3,botocore,nose,s3transfer
+
+[handlers]
+keys = console_handler,syslog_handler
+
+[formatters]
+keys = generic_format,syslog_format
+
+[handler_console_handler]
+class = StreamHandler
+level = DEBUG
+formatter = generic_format
+args = (sys.stderr,)
+
+[handler_syslog_handler]
+class = logging.handlers.SysLogHandler
+level = DEBUG
+formatter = syslog_format
+args = ("/dev/log",)
+
+[formatter_generic_format]
+format = [%(levelname)s %(asctime)s] [%(filename)s:%(lineno)d %(funcName)s]: %(message)s
+datefmt =
+
+[formatter_syslog_format]
+format = [%(levelname)s] [%(name)s] [%(filename)s:%(lineno)d] [%(funcName)s]: %(message)s
+datefmt =
+
+[logger_root]
+level = DEBUG
+handlers = syslog_handler
+qualname = root
+
+[logger_build_details]
+level = DEBUG
+handlers = syslog_handler
+qualname = build_details
+propagate = 0
+
+[logger_http]
+level = DEBUG
+handlers = syslog_handler
+qualname = http
+propagate = 0
+
+[logger_stderr]
+level = DEBUG
+handlers = console_handler
+qualname = stderr
+
+[logger_boto3]
+level = INFO
+handlers = syslog_handler
+qualname = boto3
+propagate = 0
+
+[logger_botocore]
+level = INFO
+handlers = syslog_handler
+qualname = botocore
+propagate = 0
+
+[logger_nose]
+level = INFO
+handlers = syslog_handler
+qualname = nose
+propagate = 0
+
+[logger_s3transfer]
+level = INFO
+handlers = syslog_handler
+qualname = s3transfer
+propagate = 0