Because unit tests were used to choosing a login and setting a password,
making them use such method seems easier than adapting them to use the
existing "login" method, which really works by user id and not by login.

use getId() instead of getUserName() where user is supposed to be neither Anonyous User nor System Processes.

Verify there is a single line per use.
Test summary lines on per-category level.
Always compare use by uid available on lines, not by fetching a random
document on each aggregate line.

Facilitates pinpointing faulty related key declarations.

Also by default this user will have random password

Should improve indexation performance ever so slightly.

Also, stop passing ignored "spec" parameter.

Drop overly descriptive comments.
Simplify code.
Fix coding style.

Backward compatibility was not implemented everywhere, and it is masking
bugs: not all parameters were provided to these ZSQLMethods, which can
cause all sorts of bugs and performance issues because of DTML defaulting
to acquisition context for missing arguments. Drop this overcomplex code.

by adding Base_downloadWithCors that acts like Base_download but
adds CORS headers according to Base_prepareCorsResponse.

By using Event_generateReference from erp5_crm

/reviewed-on !214

Allows accessing any catalog column after parent relation, instead of only
pre-configured columns.
Allows reverse relation lookup (for the non-parent part of the relation,
as child relationship is not supported).
Also, drop now-redundant related keys.

Simplifies extension.
Also, factorise constants a bit.

Change autocomplete from Ctrl-Space to Alt-Space, because
the former is already used for switching keyboard language.

Change indent less from Ctrl-] to Shift-Tab, because the
former is already used for switching between browser tabs.

@nexedi any objections ?

/reviewed-on !213

Including all external method arguments in the error is needlessly
verbose.
If you rely on this to debug, define this inside your external method.

Otherwise, longer results would be truncated and shorter results would
produce activities with an empty list as argument.

/reviewed-on !210

/reviewed-on nexedi/erp5!206

editable state is kept