Model test: provide better shrinking.
Model test: provide better shrinking.

The model now has a constructor Actions which holds a list of Action.
It can be used to unpack a LookAhead(M) or Try in order to shrink the program.

fpco/binary,ezyang/binary,flowbox-public/binary,flowbox-public/binary,x456/binary,bergmark/binary,basvandijk/binary