Changing the state of a relation_input gadget with value_text = ""
now updates the field.

/reviewed-on nexedi/erp5!706

/reviewed-on nexedi/erp5!705

Send 'on' value when checked.
Do not add checkbox in the request body if unchecked.

for example: SSLError: ('The read operation timed out',)

/reviewed-on nexedi/erp5!703

erp5.util.testbrowser: Require zope.testbrowser >= 5.0.0 since 5a0b3763 so update dependency accordingly.

Otherwise, the query will include a pointless "node.uid > 0" condition
(because internal API has no choice but to return a condition) which
confuses the query optimiser and may lead to very suboptimal execution
plans: a range scan of node.uid (catalog as node, node.uid=stock.node_uid)
despite provided account uid list constraining stock.node_uid.

Remove trailing whitespaces.
Make it easier to extend the list of indexed columns without causing
unnecessary diffs (sadly, SQL being SQL, those lines will still cause
extra diffs).

/reviewed-on nexedi/erp5!699

This Merge Request adds ```reachability_workflow``` and adds it to all Coordinate types  (Adress, Email etc.)
so that the can be marked as ```reachable``` or ```unreachable```.
It also adds ```coordinate_interaction_workflow```, so that when a coordinate text changes actions can be triggered.
The default behaviour is that, when coordinate text changes for an 'unreachable' Coordinate, it is marked as reachable.

We already discussed this with @jerome , but I cc @nexedi , since this can break compatibility in projects, because
in the past Coordinates acquired ```validation_state``` by their parent document (Person, Organisation, etc).
So now, if some code checks ```getValidationState``` (though it should be checking on the parent) for Coordinate, or searches Catalog with ```validation_state``` (though it should be ```parent_validation_state```), behaviour will change.

Test Result <a href="https://nexedijs.erp5.net/#/test_result_module/20180608-2D68AF16">here</a> seems good (3 failures in UI tests that seem unrelated)


/reviewed-on nexedi/erp5!691

Because the helper script for invoice, (order, packing lists, etc) printout is using `DateTime.strftime` it does not support dates before 1900.
This is a [documented behavior](https://docs.python.org/2/library/datetime.html#strftime-and-strptime-behavior) in python that dates before 1900 cannot be used.

In these cases it's not supposed to happen, but if by mistake user enter a date before 1900, printing the invoice would fail, which is not good.

These patterns were very simple and did not need strftime.

/reviewed-on nexedi/erp5!694

for Coordinates

Test also checks accessors like getDefaultEmailValidationState.

So that we can use accessors such as getDefaultEmailValidationState on
persons or organisations.

In its generic form it would declare as reachable an unreachable coordinate
when the coordinate_text changes

'coordinate' types.
Also translated_validation_state_title column to
Base_viewBaseFieldLibrary/my_view_mode_contact_listbox

To be used by coordinates (Adress, Email etc.)
so that the can be marked as "reachable" or "unreachable".

/reviewed-on nexedi/erp5!689

is used in Folder_delete, in order to decide if we would delete the object from ZODB
or do workflow transition.

Previous code was not harmful, since isDeletable check above would block
the case of existing workflow with 'delete_action' not possible in current state.
Yet, it was confusing.

/reviewed-on nexedi/erp5!696

Update Colors to patio colors

![Screenshot_2018-06-11_at_17.02.16](/uploads/d0ebc58a32df69a359e3023383fcfec2/Screenshot_2018-06-11_at_17.02.16.png)


/reviewed-on nexedi/erp5!693