Hill kinetic for pgp transports wrong

[Yuri05]

Hill kinetic for pgp transports is currently defined as
Min(X;Y)*C^alpha...

Must be:
Min(X*C^alpha;Y*C)...

E.g. currently (wrong):

Must be:

[Christoph27]

The subject of this issue is addressed (to correct the brackets in order to have "C^exponent" only in the Hill equation part of the Min-function and not in the part describing diffusion for the PgP eq. ). However, I think the Hill-equation generally needs to be reconsidered regarding the partition coefficient. I will make an extra issue for that.