Fix adding Bcc addresses from identity

Fixes that issue, but I kind of remember that there was a reason why the
updateHidden call was early in that code.

Lesson: Always comment your code, kids.
More compose window CSS tweaks; use space more efficiently
simplify
sanity checking on function input
Fix autocomplete removeEntry function

Was requiring a DOM element, not entry as the function name implies
Fix updating BCC field when switching identities
Don't set same identity multiple times