DOCS-641 geospatial review edits

Signed-off-by: Sam Kleinman <samk@10gen.com>
Minor: redundant term

Signed-off-by: Sam Kleinman <samk@10gen.com>
DOCS-1254 powerOf2 textindex and DOCS-1247 geoWithin in agg

Signed-off-by: Sam Kleinman <samk@10gen.com>
minor: wording change DOCS-1254
DOCS-1251, DOCS-1244, and some of Rassi's comments for DOCS-1188