Output interval specification

[chrbertsch]

Currently one can only specify a fixed output interval for ME simulation.
It would be beneficial to have a possibility to to also get output values at events.
So it would be best to have the following options:

• constant output interval (current implementation)
• all output values
• Constant output interval + event points

[t-sommer]

Option 3 is is actually the default for ME: sample after every step and (additionally) sample after every event. Please re-open if you need extra options.