DATETIMEFIELDUPDATE Add testFormViewEditableNextWithEditedField testFormViewEditableSaveActionContinuingEditing + update testDateTimeFieldUpdate

                                     version   | generique       | render               | onchange            | onmodification      | ideale
have A and B with empty reference,               keep typed        field reset to empty   keep typed            ?                     field reset empty
goto A, click next to acces B,
type in reference while B form is loading,
B is loaded

same with B reference = 1                        field set to 1    field set to 1         field set to 1        ?                     field set to 1

have A with empty reference,                     keep typed        field reset to empty   field reset to empty  ?                     field reset to empty
type in reference (hello),                       (hello)           ()                     ()                    (?)                   ()
click View on confirm popup,
A is reloaded

have A with empty reference,                     keep typed        field reset to empty   field reset to empty  ?                     field reset to empty
click View to reload the form,                   (hello2)          ()                     ()                    (?)                   ()
type in reference (hello2),
A is reloaded

have A with empty reference,                     keep typed        field reset            field reset           ?                     keep typed (the form decides
to update the field but should not ? no)
type in reference (hello), save,                 (hello2)          (hello)                (hello) (why??)       (?)                   (hello2)
type in reference (hello2),
focus something else,
A form is reloaded

have A with empty reference,                     field reset       field reset            field reset           ?                     field reset (user should see
the modification done server side)
type in reference (hello), click save,           (world)           (world)                (world)               (?)                   (world)
type in reference (hello2),
focus something else,
interaction add modifications to the reference
(world),
A form is reloaded

------------------------------------
So !

input.value MUST be updated on onStateChange if modification_dict.hasOwnProperty("value")
this.state.value MUST be updated on getContent
this.state.value MUST be updated on onEvent change

------------------------------------
UNRELATED NOTES

input.value reflects the typed value of the element
gadget_input.getContent reflects the typed value of the element too

input.value = "hello" replaces the current value to "hello", no matter the state of the input
gadget_input.render({value: "hello"}) does not... because gadget.state.value does not really reflects the dom value.
  if gadget.state.value was reflecting the value, then
gadget_input.render({value: "hello"}) reflects the current value to "hello", no matter the state of the input

so the form could act : while saving, listen for changes/inputs, (now saved) get the new form but ignore it, put save to orange if changes/inputs were done

rendering the gadget with the same value as rendered before causes the
gadget to be not updated even if the field has been manually edited.

/bug #20190204-39AF19
https://nexedijs.erp5.net/#/bug_module/20190204-39AF19

checkValidity calls getContent, which uses the same mutex

Improve the query speed by using the default listbox sort.

OfficeJS's user blocking third party cookie will at least stop entering their credentials many times for nothing

Followup of nexedi/erp5@340accd1

Conflicts:
	bt5/erp5_web_renderjs_ui/PathTemplateItem/web_page_module/rjs_gadget_erp5_nojqm_css.xml

In ERP5 software release we now have `mock` egg installed, so we can use it in tests instead of doing manually like this:

```python
saved_method = Class.method
def patched_method():
  ...
try:
   Class.method = patched_method
   ...
finally:
   Class.method = saved_method
```

/reviewed-on nexedi/erp5!882

Change the caching policy to one hour.

Use the CDN to publish the page if the backend is down

Cache the manifest like the HTML page but force refreshing the manifest to prevent CDN cache inconsistency.

Defining it inside portal_components ledds to business template update issue.
Bypass it by defining the expected behaviour into the web section hook.

Allow the CDN to cache the content.

Use stale_if_error to allow the CDN to return content if backend is down

Unify Vary Header.

erp5_banking_cash depends from erp5_trade via erp5_banking_core.

Gadgets:

* Support `changed` flag from `erp5.js`: 

![unsaved changes sreenshot](/uploads/cff30eae0a5d87df26bac13d43e1da3f/image.png)

* Comply with translation protocol used in ERP5JS. This does not translate, because it would not be easy ( ERP5JS translate client side with a json database of message, but in xhtml style the translation is performed server side with localizer) and not so important now. What matters is just that we can somehow reuse gadgets.

Style:

* While we are at it, fix a minor annoyance that the button in "long" dialogs where not easy to reach, at least on chrome

![before](/uploads/e03a8311571806a55fd72f6923cf855a/Screenshot_2019-05-31_at_10.38.05.png)

![after](/uploads/5753bc44fbc0f69b6adfeb14b3367236/Screenshot_2019-05-31_at_10.38.37.png)

/reviewed-on nexedi/erp5!880

Remove all globals to allow multiple live tests running on the same page.
Stop reading the test output if the browser tab doesn't have the focus.
Stop hardcoding the URL in the javascript.
Stop hardcoding other fields path in the javascript (+ embed the textarea in the gadget).

Propagate all parameters via formulator.
It will allow to use this gadget from another context document.

Run live test from the RJS UI

This way we can use gadgets using of ERP5JS translation API in xhtml
style.
This is really minimal compatibility layer and translation is not
actually performed.