Settings (height, rendering etc.) on a per (random) facade-type basis.

[ElmarJ]

Allow users to specify different custom building specification, including (but not limited to) the facade material, default height, UV-settings and pointed roof-settings as basis for random seection. This further expands the current random selection of only the facade material, and allows users to specify several "types" of buildings, each with their own specifications, to randomly choose from.

Particularly necessary to implement realistic pointed rooftops, as these settings have to be customized on a per-material-basis (see also ElmarJ/waterlooplein-timemachine#3).