Possible new features for future FLORIS releases

[misi9170]

Allow specification of a single (or possibly multiple) findex when calling sample_flow_at_points and sample_ti_at_points, see #1139

[misi9170]

Separating internal and external farms, see this comment.

[misi9170]

Non-wind turbine wake generating objects (e.g. external wind farms, buildings, forests, fences, etc)