insert initial states

[timziebart]

The states argument of topology_classification should be able to contain default values for know user input.

E.g.

1. stable fixed point of default evolution in sunny region is always part of the shelter.
2. Or stable fixed point of the management in the sunny region are at least backwater, but can be upgraded to lake, glade or shelter.

This should fix some problems generically arising during the integration when the right hand side is normalized (or when the distance thingy is implemented).

[timziebart]

Could be used in order to give other information, too. E.g. For the Population and Resources a, we know that everyhting has to be upstream.

[timziebart]

todo: Rebekka adds stuff for initial states with upgrading

to be done later on (maybe):

• upgradable initial states
• more general initial information (e.g. I know everything is upstream ....); probably similar to calculating only partial TSM (e.g. only upstream, or only downstream ....)

[timziebart]

upgradeable initial work states depend on #18 first (:

maybe we should use the word given states instead of "initial states" from now on, because that seems less confusing to me