MATSim Code

in cadyts, the controlerlistener ("context") is now responsible for registering selected plans with the calibrator

MATSIM-215: Allow getValue() to return <null>: getParams() does in this case also puts the "null" String

Most tests expect this behavior (and the getParams() code goes in this
direction as well)

MATSIM-215: pass remaining config groups to ReflectiveModule

almost all use RefelctiveModule, and all understand null now.

MATSIM-215: playgrounds and contrib ignore "null" in add_param

MATSIM-215: fix more config groups using ReflectiveConfigGroup

MATSIM-215: fix StrategyConfigGroupTest

implied also fixing other default modules, that failed in the IO
process. Fixes are mostly amoving from ConfigGroup to
ReflectiveConfigGroup, allowing to get the automatic handling of null
strings.

answer a comment

MATSIM-215: update example

MATSIM-215: update ReflectiveModule tests

MATSIM-215: ReflectiveModule understands and converts null strings/pointers

can be deactivated for any parrameter, if needed