This was inefficient for two reasons:
- any message we could validate during current iteration means a message we
  did not consider is now in the range we just scanned. And it will not be
  considered until validation node starts over and scan this same range
  again.
- "LIMIT x,1000" pattern on >1000 messages causes a quick-growing number of
  extra rows scanned by the SQL database just to skip the "x" first rows:
  at 2000 rows present it must scan 1000 + 2000 = 3000 rows for a complete
  loop over all pending activities. At 3k rows it must scan 6k rows.
  At 4k, 10k.
  While this is an overestimation (some rows should be possible to
  validate, so these would be scanned once only), this overhead grows so
  large that this overestimation can become negligible.

Instead, use a range condition consistent with query's "SORT ON", which is
already efficiently materialised by an index: SQL database just has to
dive into the existing index to start just above the last message from
previous iteration, and resume scanning from there, solving both issues
listed above.

This method is called on every __getattr__ (guarded_getattr, actually) of
every restricted python scripts. Which means each "." in the code triggers:
- traversal to relevant acl_user folder
- a user lookup
just to get the same value throughout the execution of a script (as its
owner does not change during execution).
Also, in practice we have extremely few possible owners: very few users are
allowed to edit code in an ERP5 instance, and if such instance is managed
using the upgrader alarms, they will even further reduce this owner set to
System Processes only.
On a real-world web page rendering, this reduces the total number of
traversal calls from 1500 to 1100, getting rid of the two hottest spots:
/acl_users and /$site_id/acl_users .

But category group should be used to support all arrow categories.

/reviewed-on !755

/reviewed-on !720

* Instead of Person.reference, Person.user_id is now used to log in (fe27a9c3).
* Fields text were renamed to follow naming conventions (329c196d).

/reviewed-on !770

/reviewed-on nexedi/erp5!763

This snapshot were made on Chrome 70 (ChromeOS) with a 1001x932 window
(innerHeight x innerWidth)

To Compare a "screenshot" of a DOM element with a reference snapshot.

This check supports the following parameters:
 *   locator - an element locator
 *   misMatchTolerance - the percentage of mismatch allowed. If this is 0, the
      images must be exactly same. If more than 0, image will also be resized.

https://github.com/niklasvh/html2canvas Copyright (c) 2012 Niklas von Hertzen

from https://github.com/HuddleEng/Resemble.js/blob/v2.10.2/resemble.js © 2013 Huddle

to get stable sort and prevent "random" test failures.

"Restore" sounds a bit strange to me in this context.

So that we can wait for this in the tests

[erp5_officejs] Use upload_dict instead of file_extension to check for correct file-type during notebook upload

Also, exlicitly specify the txt extension during download

/reviewed-on nexedi/erp5!760

/reviewed-on nexedi/erp5!762

Also, update tests for notebook to check for Upload page

/reviewed-on !764

Fixes rendering when using Chameleon:
  ValueError: only strings can be translated, not: <ERP5Type.Message.Message for ...

/reviewed-on !747

/reviewed-on !765

adjust font url

This is incubator-echarts-4.1.0-release/dist/echarts.min.js from
https://github.com/apache/incubator-echarts/releases/tag/4.1.0-release

https://www.erp5.com/documentation/developer/guideline/coding/erp5-Guideline.Coding.Best.Practice#use-methods-to-access-properties-in-erp5