DOCS-2168: fixing typo
DOCS-1657: db.collection.copyTo is not documented

Signed-off-by: Sam Kleinman <samk@10gen.com>
DOCS-2159: moving sharded cluster security section to security from sharding
DOCS-2157: removing copyIndeses pending SERVER-11418
DOCS-2119: fix for mongorestore example
DOCS-2111: adding missing note