- update PresencePeriod.getNextPeriodicalDate with fixes from 6155f7ff
 - do not use addToDate, but simply DateTime arithmetics that unlike addToDate, works correctly

Up to now, once all test result lines in draft were processed,
test result lines already started where affected to all test nodes.
It was designed like this in case the initial affected test node was
unable to finish is work (test node or machine could die for various
reasons). But having a testnode dying should be rare, thus optimisation
should not consider that this happens all the time, even though we
must take into account that this could happen.

This was leading to cases where a testnode, instead of quiting a test
suite to process another was affected a test already affected. So it
happened that we loosed one hour of a testnode while it could do much
more useful work than repeating the work of another testnode.

Thus, consider that testnodes are usually able to process their work,
and make testnodes immediately work on another test suite once all tests
of a test result are started.

Then, run regularly an alarm looking for stuck test to restart them
in order to affect work already affected only when required.

This change should make the system more reactive when things are working
(wich is the majority of time). Not working cases would still finish
to work, but in a less reactive way. If we wait urgently for a test result
and we see that a test is stuck, there is also possibility to unblock
it by hand (if we do not want to wait the alarm).

Cloning a movement as same effect as creating a new one and editing it, so make
sure interaction usually called when editing a movement are called when a movement
is cloned. Otherwise we can get parts of simulation tree missing.

I missed it in commit b0209091

This fixes a regression in commit b9c41350

Commit b45914fa changed the return value of
getFunction() to return more information. But it's easy to preserve the
previous API for any code that would use it, and anyway, it became misnamed.

simplify error handling and avoid code duplication (thanks Romain for advices)

Instead of trying without and retry in case of TypeError, we now have a reliable
rule: aq_parent is passed if and only if the name of first argument is 'self'.

The main optimization is the replacement of
  erp5.component.extension.find_load_module
by a simple
  __import__
like it was before commit c2ce3ba0

Use it on PythonScript & ExternalMethod.

- Code refactoring and small optimizations.
- Really fix unwanted acquisition.
- ExternalMethod: fix security declarations.
- Fix role/permission checking for ExternalMethod called by a PythonScript
  with proxy roles.
- When editing an existing guard, modify it instead of always recreate one.
  no very useful here, but that's good practice: this is nicer for the ZODB
  and it's easier to browse the history. BT should do the same when upgrading.

If for some reasons, this gadget does not get results (usually due to network failures or
service unavailable for other reasons), do not fail and retry until it works again

To be consistent with other type information classes such as
SolverTypeInformation or PDFTypeInformation.

At the same time, describe a bit more

- use `obj.data` instead of `str(obj)` to get File object content
- fix data_uri split unpack issue
- fix str/unicode encoding errors
- fix allow parse url list in css

erp5_upgrader: TemplateTool_checkCategoryNameConsistency constraint can update categories which have moved

[erp5_web_renderjs_ui] Update website modification, to prevent launcher gadget modification date to be more recent

- WebPage_exportAsSingleFile
- WebPage_extractReferredObjectDict

when converting an image, the returned value of img.convert
is not everytime a string. It might be a kind of acquisition
value