Error checking for 'extra-locales'

If it's a directory and it exists, delete it.
If it's something else - bail out.
Then create it and do the same as before.
Remove js for elements which no longer exist.
Remove trailing whitespace.
Shift unimportant sections stuff to speeches.js.

There was some javascript temporarily residing in the speech form
template. Shift it to a more appropriate permanent home.
Add a date picker for speech and section forms.

Bootstrap has been removed, but we were still trying to use the
bootstrap date and time pickers. Replace the date picker with
a foundation one. For the moment we'll just put the time picker
back to a text box with a placeholder.

I can't see autoclose mentioned in the fdatepicker docs, so I've
taken that out - the new datepicker seems to close when a date is
selected anyway.

Fixes #366.
Don't set a minimum end date based on start date.

With this as it was, if the start date were erroneously set too far
in the future, and then brought back, the picker for the end date
was stuck with only accepting dates after the original start date.

We should have a proper think about how to make the javascript keep
the dates and times consistent.
Localize formats of dates when adding speeches and sections.

The formats for acceptable dates and the placeholders now change
depending on the language you ask for.
Remove redundant code.

These lines were only needed to keep bootstrap happy.
A bit of PEP8ification.

Not getting speeches/forms.py down to 0 flake8 messages though, as
there are a few things I can't see a nice way to do.
Update translation strings.