Update Logger.cfc

Added ability to just thread logMessage at will by a configuration, instead of having a separate "AsyncSomeAppender.cfc" for every time you need to thread something.
Configuration is simple, uses the already existing "properties" argument struct when registering an appender to watch for a new key called "async" which must be true.

For example, this logBox struct which is the default in the application templates, makes the ConsoleAppender threaded just be passing the properties={async=true}.

		logBox = {
			// Define Appenders
			appenders = {
				coldboxTracer = { class="coldbox.system.logging.appenders.ConsoleAppender",properties={async:true} }
			},
			// Root Logger
			root = { levelmax="INFO", appenders="*" },
			// Implicit Level Categories
			info = [ "coldbox.system" ]
		};