Editor Field does not escapes value, String Field does.

also :
* remove Accept-Encoding from Vary header, because Zope's response does not differ by Accept-Encoding request header.
* use getModificationDate() for modification time if available.

Editing a text containing </textarea> was breaking the field

this commit fixes the following commit :
* patch : Caching Policy Manager should not override existing response headers.

erp5_web_renderjs_ui: create link when a sub field is not editable but it's in listbox's editable column

We have to use destination since this what we define on production orders (not source).
Make sure we display correct values if a resource is used by several lines.

invoicing: invoice transaction builders should find corresponding deliveries only through explanations

What happened before :
- user confirm sale invoice
- activity for building vat invoice lines is created
- user change destination_section
- since builder was expecting having same destination_section on delivery
and simulation movements, it was failing

Now, the builder does not look at source/destination or other categories, it only looks
for common explanation. This can be done this way only because transaction lines should
go inside the same delivery as invoice lines with standard invoicing.

CaptchaField: set no-store cache-control header to be consistent with our caching policy manager configuration.

Auto planned movements are not only draft, it could be very useful to take such
movement into account when doing stock optimisations

Up to know, order builders were mostly used having in mind the idea of
deleting all previously created automated orders.

This way was mostly requesting to run generated delivery builder only
once per night, assuming there is no users working at that time.

So to allows running very often (many times a day) generated delivery
builders, allow them to update existing deliveries. This way :
- automated deliveries could be much more up to date
- there is no need to delete everything
- this generate few activities, there is no need of a long calculation
  to update everything

Also, the stock optimization was using dates with a precision of one
full day. Generic code must support much better precision.

Commit dc00a308 removed link on the cell.

Speed up jIO synchronization by allowing fetching multiple documents JSON with one request

Round floats before testing for equality