The recently added --frontend_url parameter breaks all existing runUnitTest
scripts that don't accept it, and because this option is irrelevant for many
of them, we don't want to force everyone to update their test suites.

Similarly, parallelizing tests is not worth the effort for some test suites,
and currently, their runUnitTest scripts contain ugly lines like:

    parser.add_argument('--node_quantity', help='ignored', type=int)

These 2 parameters are now passed to runUnitTest only if it supports them,
like it is already the case for --firefox_bin and --xvfb_bin.

Otherwise, the user sees nothing at all whenever she's not allowed to view
at least 1 test suite.

This fixes commit 63b3ccda

ConnectionError does not have status_dict

revert a change submitted by mistake

This allows to have some information when testnode fails running a test suite

Now the test node sends a  `--frontend_url` parameter to the test suite, which an IPv4-enabled URL to the test node's backend. This is required to run remote tests on environments without IPv6 connectivity. 

Also the SlapOSController now waits 20 seconds instead of 10 seconds for the SlapOS proxy web server to start answering requests. On slower machines 10 seconds weren't being enough.

@Tyagov, please review.

/reviewed-on !189

Some tests are sensible to Daylight saving time when they do some checking
with non fixed dates

mrp: allow edition of line quantities even if industrial_phase is set (and in general, even if option categories are set)

HTML is directly injected in the DOM.
CSP should prevent to execute JS/CSS.

Before fixing this bug, 'listbox_previousPage:method' input button was
submitted but with no value (''). However, this was not handled by the
backward-compatibility code and thus next/previous page buttons would
not work properly if erp5_xhtml_style is not updated.

Only 'float' supported for the moment. This should cover the case of integers.

Example of 'Sortable Columns' value in a ListBox:

  id | float
  title |

Since there's a fallback to 'Searchable Columns' when 'Sortable Columns' is
empty, the cast type can also be specified there, in order to avoid duplication.

Use new renderJS job to simplify the code

Support will be removed with CSP

Support calling render multiple times

Support calling render method multiple times.

Try to reduce possible errors when 2 functions tries to update the listbox DOM