Document replIndexPrefetch.
changing wording of boolean text search
DOCS-1496: delegated authentication and anyDatabase roles.
DOCS-1469: clean up superuser language on auth tutuorial
DOCS-1480: enterprise installation tutorial
DOCS-1480 clarification about useradmin on admin database
Fixed several duplicate terms

Signed-off-by: Sam Kleinman <samk@10gen.com>
minor: formating changes to yaml tables
Use boolean instead of string for db.currentOp

Signed-off-by: Sam Kleinman <samk@10gen.com>
DOCS-1501: diagram of 3-member replica set.

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