Returns a property which is simply an alias for another property.
Acts simply to provide another name to reference the same underlying attribute; useful when subclassing, where a subclass might have a more descriptive name for an attribute that has the same function.
The only purpose of this function is to produce more readable code.
Example:
>>> class GenericExporter(object):
... def __init__(self, outFile):
... self.outFile = outFile
...
>>> class CowExporter(GenericExporter):
... cowFile = alias('outFile')
...
>>> CowExporter('bessie.cow').cowFile
'bessie.cow'