Start a fresh experiment, from scratch.
		
		Returns `self`.

def fromScratch(self):
		"""Start a fresh experiment, from scratch.
		
		Returns `self`."""
		
		assert(not os.path.lexists(self.latestLink) or
		           os.path.islink (self.latestLink))
		self.rmR(self.latestLink)
		return self