DOCS-353 killOp and foreground index ops
DOCS-353 added note to current ops page
DOCS-861 findAndModify and upserts can insert multiple documents

DOCS-861 findandmodify upsert clarification

DOCS-861 findandmodify upsert clarification

findAndModify flesh out what is returned

DOCS-861 multiple invocation of findAndModify and flesh out results
DOCS-954 eval() helper and nolock

DOCS-954 db.eval() method and nolock option

DOCS-954 incorporate Scott's feedback

incorporate Tad's comments

DOCS-954 eval and lock
minor: fixing broken cross references
DOCS-954 eval and locks
minor: indentation fixes
merge: DOCS-654
edits and more clear single sourcing
merge: DOCS-861
clarification to find and modify command style
merge: DOCS-353