Use correct forms for geo class pref labels and definitions

[rjyounes]

GeoRegion, GeoSegment, etc.: Are they hyphenated, a single word, two words? Right now we use two words such as "Geo Region," which doesn't look right to me. There may be variation from case to case but we may still want to adopt a standard form.

As long as we are looking at these terms, we should correct the definitions so they reference ordinary language rather than class names - e.g., "geo-region" instead of "Geo Region" in the definition of GeoSegment.

[uscholdm]

@rjyounes 's suggestion makes sense.

[rjyounes]

Should be folded into PR #1203.