Allow buildings to have several types

[chapuisk]

Is your feature request related to a problem? Please describe.
There is no way in the model to define building so they may host several activities within: e.g. a homeplace that is also a shop, a shopping center that also host restaurant and dentists.

Describe the solution you'd like
Turn the type attribute of building into a list of type.

Describe alternatives you've considered
Currently, I create mixing type (e.g. home_work) and connect it with several activity types in the Building type to activity type.csv parameter file