Added the load procedure to read CCS expressions from files.
Added a test ccs file.
Made lts.sml load "Int".
Swapped load and ccs to be in the right order.
Prevented load from overriding the SML standard load procedure.
Updated the *.ccs samples.
Added iter.
Implemented most of Hermanns' stepper functionality.
Missing:
	- show should print bindings
	- CCS.toString should not print double backslashes (\\) when its output is not meant to be given to dot
	- We need documentation!
Moved the samples to 'samples'
Updated zip.sh to include some ccs samples.