Improve handling of bash history

[borellim]

This partially addresses marvel-nccr/quantum-mobile#125
I'd like to release this as v1.0.7.

[chrisjsewell]

Cheers. I guess you could make these numbers variables (set in defaults/main.yml) if you want, but ok if not

[borellim]

Thanks. True. For now it seems very self-contained, though, so I think it's fine.

Another thing: these changes are only applied to the max user, not vagrant. I assumed that's ok.