We were converting markdown to HTML every time we saved a record, which
has the same problems as sanitizing HTML before saving it to the
database, particularly because the body of a legislation draft is stored
in a translations table.
Performance-wise this isn't a problem: converting a text with more than
200_000 characters takes about a milisecond on my machine.
Note we need to modify a migration generated by globalize, since the
method `create_translation_table!` would fail now that we don't define
`translates :body_html` in the model.
So now we test in depth at the model level, and can be a bit more
relaxed about integration tests for translations.
Note we're defining some extra factories to make sure all translatable
attributes with presence validation rules are mandatory. This way we can
simplify the way we obtain required fields, using `required_attribute?`.
Otherwise, fields having an `unless` condition in their presence
validation rules would count as mandatory even when they're not.
Updating it required reorganizing the form so translatable fields are
together.
We also needed to add a `hint` option to the form label and input
methods so the hint wouldn't show up for every language.
Finally, the markdown editor needed to use the same globalize attributes
as inputs, labels and hints, which adds a bit of duplication.
