Fixes broken test on master

/reviewed-on nexedi/erp5!374

Restricted: Allow datetime module class attributes.
    
To allow the class attributes, we add a helper method ``allow_class_attribute''.
 Why addng this is because allow_module can allow instance methods but not class
 attributes.
 For example, datetime.datetime.now(), datetime.datetime.max, dict.fromkeys(),
 Decimal.from_float(), epoll.fromfd(), itertools.chain.from_iterable() are class
 attributes in Python 2.7.
    
 Also, add a special in-advance-import for datetime.datetime.strptime().
 It is because datetime.datetime.strptime() imports _strptime by C function
 PyImport_Import which calls
 __import__(name, globals, locals, fromlist=['__doc__'], level=0).
 The "level=0" is not supported by AccessControl in Zope2. At the same time,
 the dummy from '__doc__'  is neither allowed in it by default.
 Therefore we import _strptime in advance in this monkey patch file.
 This prevents both importing _strptime with level=0, and accessing __doc__,
 when calling datetime.datetime.strptime() in Restricted environment.

/cc @vpelletier @jm @klaus

/reviewed-on !275

erp5_officejs_support_request_ui: Check the "Empty Criterion is Valid" checkbox in "Unsafe" web section.

Without check the "Empty Criterion is Valid", the web section will return nothing. But due to a bug, the web section will return all documents anyway. This should be checked.

Rename `rjs_gadget_erp5_pt_listpage*` to `gadget_supportrequest_pt_listpage*`.
Rename `rjs_gadget_erp5_pt_form_view_discussable*` to `gadget_supportrequest_pt_form_view_discussable*`.

Web pages which ID starts by `rjs_gaget_erp5` will be include in `erp5_web_renderjs_ui` bt5. We want the custom page template only be included in the `erp5_officejs_support_request_ui`.

Rename the title of left chart to "Support Requests Pipe", right chart to "Last Month Activity"

And replace devellopement by app in titles

ECharts has better visual effect than Chartjs.
And also update the tests.

If strict_language is False, a document having the other language is
chosen if the specified language one is missing.

all_languages=True returns results grouped by (reference, language) so
that we can have several documents for a single reference.

strict_language=False returns results grouped by (reference,) only,
with considering the language priority, thus we have only one document
for a single reference.

catalog: portal_type=None or effective_date=None should mean the good default value in SQLCatalog_getDocumentValueList.

so that the utility script calling this can have arguments like
portal_type=None, **kw and have code like
getDocumentValue(portal_type=portal_type, **kw).

Sections must be in table order: table_0 and table_1 in first section, then
table_3, then table_4 and query_table must be in last query section.

No related key should hardcode "catalog" table name (or any other table
name, for that matter), so just let column mapper work.

Also, simplify code flow by removing unnecessary "if" statements.
Also, simplify returned query tree by removing unnecessary intermediate
ComplexQueries.