This resolves issue #273

updated examples

This resolves issue #273

At each step we first check for possible malfunctions.
THen we apply them and do all the agent steps
At the end we look at what agents should be fixed. This lead so to:

Current malfunction value says how many step calls are necessary till agent can move again

e.g. malfunction = 2, we have to call step() twice untill the agent can move again.

Code cleanup

It now gives the probability that an agent breaks at given time step
given the number of agents and the rate of failures of a single agent.
These number now need to be much larger.... otherwise we will have alot of failures

Updated example

Adresses issue #263

Adresses issue #263

calculating max possible number of cities and aborting if only one city can be built. Also updated the way we chose city orientation.