Loads a set of properties from source and returns them as a new Properties object. The load source can be either the string name of a file, a File object, or a Stream object. Properties are read from source as individual lines using lineIn. Blank lines and lines with a Rexx line comment ("--") as the first non-blank characters are ignored. Otherwise, the lines are assumed to be of the form "name=value" and are added to the receiver Properties value using name as the index for the value.