Allow to overwrite this inside project to init Properties like reference.

Because it is mainly used from the 'initsite' zope.conf section, the passed
value is often a string, hence the automatic cast to integer.

The default is defined in erp5_core: 1
The specific value '0' disables storage in ZODB.
Another other value sets the interval.

- Use unrestricted _edit method on reportTaskStatus - restrictedTraverse applies security anyway
- Remove some useless code
- Fix TypeError: stopUnitTest() takes exactly 3 arguments (4 given)

In order to use setting in multiple application on same domain.

/reviewed-on nexedi/erp5!474

createTestResult is called also without node_title, and it shall allow
execution in such case.

Such parameter can produce undesired conditions
(ex: FROM catalog as node, ... WHERE node.uid > 0 AND ...) causing poor
performance. So avoid introducing this parameter when its value is empty.

There is no need for any client to call tool directly.

This results with calling correct methods on the server.

This results with calling correct methods on the server.

The module is to access Distributor not the whole tool.

This results with calling correct methods on the server.

Since distributor is used, tests need adaptation:

 * created default Test Node and Test Suite, required by
   Distributor.createTestResult
 * adapted _createTestResult to reuse created documents
 * adapted some tests in order to reuse created documents

Several changes to `Item_getTrackingList`.

My original goal was to fix a problem happening when users sort the listbox by `source_title` column. Because catalog understands it, it adds a join condition which would filter movements not "directly" having a source (ie. having a source by acquisition from parent). 

Then I realized this script was doing a lots of catalog queries that are done in a most efficient/safe way on the brain, so I switched to this.

Also add a few missing tests.

I did not add test for my original problem, because the real fix is that listbox should not declare `source_title` to be a sortable column, because this method does not support it.


/reviewed-on !469

rJS gadget uses text content as value