Allow standard appenders to be configured by name (instead of full path)

An appender declaration might look like so:

This can be a bit cumbersome to type and read. Allow JUST the appender name to be passed into the class parameter for brevity like so:

If the string has at least one period, assume it's a full path, but if not automatically append on the coldbox.system.logging.appenders bit.

For an example of where we've done this, look at the eviction policies for CacheBox.