Storage related attributes

[Dmytror]

Dear Antti,

thanks, adding HETHTHP commodity helped! We are doing our best to move our models from the old VEDA to the new one. Hope that VEDA related issues will not be a problem soon.

Ah, I have changed it back to STG in order to compare model results with a storage process being described as STG and STS. This is simply a learning exercise. But thanks for this attention to details and bringing this up.

Thanks again,
Dmytro