Update diagnostics.txt

grammar fix

Signed-off-by: Sam Kleinman <samk@10gen.com>
minor: cleanup artifacts
DOCS-2605: clarify organization of db.collection.remove
DOCS-2527: ttlMonitorEnabled documentation
DOCS-2579: slight reorganization of security tutorials
DOCS-2608: fixing jumbled sentence
DOCS-2609: fixing objectID sentence
DOCS-2567 audit message details
trivial - change wording of a sentence
Update backup and restore role docs

The backup server doesn't do restores directly, so we shouldn't mention the backup service in the docs on the "restore" role.  Also added reference to mongodump and mongorestore.

Signed-off-by: Sam Kleinman <samk@10gen.com>
edits to built in role page
Fixing copy-paste typo in documentation

Signed-off-by: Sam Kleinman <samk@10gen.com>
DOCS-2412: upgrade note about the backup agent and 2.6
DOCS-2620: reorganize sharded cluster organization
DOCS-2619: edits to clarify background index building compactness
trivial: change overtime to 2 words, fix spacing
fix restart-index-builds-after-shutdown issues
minor: reorganization of releasenotes page
Update fsync.txt

fsync+lock is not a shard-level operation, but a node level operation.

Additionally, it's critical to explain that fsync+lock is intended only for making file-system-level backups, and that
reads are not guaranteed not to block. (So that people don't
try to use this in conjunction with mongodump, which isn't
guaranteed to work, and sometimes hangs on people.)

Signed-off-by: Sam Kleinman <samk@10gen.com>
DOCS-2614: edits to fsync page