cold emission hydronic: Key error

[kuhnal]

This does not work. I will search for the problem tomorrow.

[Linwal]

Yes, the choice hydronic which was introduced for "no air conditioning" does no longer work, the cold emission now needs to be one of 'air', 'radiator', 'floor heating' or 'ceiling heating' or also 'None' in the configurations.xlsx file

This change came with #94 when dynamic heat pump COPs were introduced and therefore heat and cold supply temperatures were required.

@Linwal: Add this to documentation. (Documentation on inputs would be great!)

[kuhnal]

Thank you for the clarification :)