check pydot version at runtime

to avoid using an older version, because it causes failures in tests.
raise Exception if jtlv output is malformed (e.g. #?# appears as value)
add test for jtlv returning #?# as value
use integers as states of FTS returned by `discretize`

and update the relevant test
add script to run all examples and stop at first error
Merge branch 'strategy' of https://github.com/tulip-control/tulip-control into partial_obs
revert find_controller back so that it works with integer states'

ls
Merge branch 'partial_obs' of https://github.com/necozay/tulip-control into partial_obs

Conflicts:
	tulip/abstract/find_controller.py