DOCS-4465: edits to driver compatibility with large replica sets
DOCS-4488: add release notes, changelog for 2.6.6

Signed-off-by: Sam Kleinman <samk@10gen.com>
DOCS-4488: edits
edits to 2.6 release notes
options: data clean up
DOCS-4486 geojson area restrictions
DOCS-4488: more tickets for the 2.6.6 release notes
DOCS-4488: more tickets for the 2.6.6 release notes