need to strip trailing <br /> when saving fields
experimental type answer refactor

- when answer not correct, show both the given and correct string in separate
  markup. we use red/green for the given string to indicate what was correct,
  but we use grey rather than red on the correct string to indicate what was
  missing, as red is misleading
- colours can now be customized in css with .typeGood, .typeBad and
  .typeMissing
- answer now shown in monospace so given/correct lines up; can be customized
  with code#typeans
- do away with 'correct answer was' text that people didn't like
a hack to ensure hr falls before answer comparsion
add real example to card layout, and move hr like during review