re-add a few explicit checks on sheets size

remove email settings from spec files

version bump. document flush

Improve get drivefile (GAM-team#756)

Addresses Issue GAM-team#755

Add new options:
targetname `<FileName>`
overwrite
showprogress

no quotes

Merge two approaches for GAM header on SA

- Ross approach put headers on both SA token generation request and API calls
- Jay approach appending to existing header if it exists

GAM 4.32

What's new in 4.31

whatsnew.txt for 4.30

GAM 4.23