Use 'compact controls' for spreadsheets

[cscott]

See comments in #93. It is apparently possible to set up google spreadsheets to use 'compact controls'. Can we automate this? If we clone an existing spreadsheet, will it inherit the 'compact controls'?

[cjb]

It looks like Google (now?) remembers Compact Controls on a per-user basis, so people will have to enter Compact Controls mode once on their own, but after that it should persist as they open new spreadsheets.

[Torgen]

Did a little research here. Apparently there's a rm (for render mode) query param. Some values and their effects: rm=embedded hides the title and icon but shows the menubar and toolbar above the grid rm=demo shows only the toolbar above the grid rm=minimal shows only the grid. I think rm=embedded is what we want, since there is potentially useful stuff in the menus and you can't get them back in demo mode but embedded mode does let you collapse them for extra space when you don't need them.