DOCS-2006: mention write concern for chunk deletion

Signed-off-by: kay <kay.kim@10gen.com>
DOCS-2006: fix wording based on Sam's feedback.

Signed-off-by: kay <kay.kim@10gen.com>
DOCS-2006: clarify write concern for chunk migration

Signed-off-by: kay <kay.kim@10gen.com>
DOCS-2006: fix syntax; clarify admin db

Signed-off-by: kay <kay.kim@10gen.com>
DOCS-2006: write concern and namespace fixes

Signed-off-by: kay <kay.kim@10gen.com>
DOCS-2006: clarifications from Kay

Signed-off-by: kay <kay.kim@10gen.com>
DOCS-2006: wording fixes and admonition removal

Signed-off-by: kay <kay.kim@10gen.com>
DOCS-2006: further clarifications and cleanups.

Signed-off-by: kay <kay.kim@10gen.com>
DOCS-2006: fix write concern and wording stuff

Signed-off-by: kay <kay.kim@10gen.com>
DOCS-2006: minor fixes

Signed-off-by: kay <kay.kim@10gen.com>
DOCS-2006: remove references to write concern

Signed-off-by: kay <kay.kim@10gen.com>
DOCS-2006 cleanupOrphaned and chunk migration edits