lat-lon processing

[tucotuco]

Before creating index on unique lat-lon, preprocess the verbatim input to create seven-digit precision string version (including rounding) and remove invalid lat-lon pairs (e.g., lat or lon invalid). For VertNet, also include the condition where lat and lon both zero as an invalid value. This will trap inputs that have 0 for null. VertNet is extremeley unlikely to have any real data from lat=0, lon=0, while it is likely to have a lot of data from these false values.

[eightysteele]

Thanks man, assigned the issue to myself.

[tucotuco]

Let's not do this in gulo. It's not the place for data quality improvement.