fix the name of a property in the UI (for S)

It looks like it would be a bit more involved to support checkbox inputs
being checked by default, and it also would currently always put
jr:noAddRemove="false()" when leaving out the property is sufficient.
remove itext id from form content export (Case:56308)
Merge branch 'master' into repeat-add-remove
Merge branch 'master' into export-columns
add non-default languages to form content export for image, audio per amelia
Merge pull request #52 from dimagi/repeat-add-remove

Repeat add remove
remove vunused variable
fix Case:58845 (missing error when display text but no question itext id)
fix Case:58847 (adding a question takes painfully long on large forms)

Currently when you add a question on a large form it can take several
seconds.  This is because every time a question is added every single
question in the form is validated in order to redraw the error icons
in the question tree.

This change removes that and makes adding a question snappy on even very
large forms.

Revalidating all questions seems unnecessary because this is already
done on form load and when you change a question that question itself is
automatically validated.

Since by default questions are created in a valid state (non-duplicate
question id, etc), adding a new question never introduces new validation
errors until the question is edited to be invalid, and anyway if the
question wasn't created in a valid state you would see an error as soon
as you edited it.

As far as I can tell validation only occurs isolated to each individual
question and there is no structural validation except for a few things
like unique question IDS.
Merge pull request #54 from dimagi/case-58845

fix missing error when display text but no question itext id (Case:58845)
Merge pull request #55 from dimagi/case-58847

fix Case:58847 (adding a question takes painfully long on large forms)
Merge pull request #53 from dimagi/export-columns

remove itext id from form content export
don't consider empty display text to be missing display text (Case:59317)
Merge pull request #56 from dimagi/case-59317

don't consider empty display text to be missing display text (Case:59317...
Merge branch 'master' of github.com:dimagi/Vellum into add-question-redesign