move speech form styling into the sayit app
hide "back to top" link on speech authoring page, to avoid confusion with submit button
fix inconsistent margin under select2 elements
standardise capitalisation of "Log in" and "Sign up" in a few more places
Merge ssh://git.mysociety.org/data/git/public/sayit.mysociety.org into 241-signup-tweaks
Merge branch '241-signup-tweaks' of ssh://git.mysociety.org/data/git/public/sayit.mysociety.org into 241-signup-tweaks