Fix typos in the 'New Default Allocation Strategy' release notes.

This commit adds some missing words, fixes 'newCollectionsUsePowerOf2Sizes'
casing and changes ':collmod:`usePowerOf2Sizes`' to ':collflag:`usePowerOf2Sizes`'.

Signed-off-by: Sam Kleinman <samk@10gen.com>
DOCS-2595 index filter query predicate wording changes
Update introduction.txt

Signed-off-by: Sam Kleinman <samk@10gen.com>
trivial - clean up various method yaml files
DOCS-2674 cleanuporphaned
DOCS-2637 setOnInsert for findAndModify
minor: fixing broken footnote