By using pattern r'push.*undef' files has been selected, and for each obvious
place error handling has been delegated to global error handling system and all
places found with silent catching errors has been marked with XXX-catchall with
optional explanation.

It's a workaround for issue in monitor resulting with infinite recursion after
clicking delete button.

Thanks to not starting backend separately, the test became much simpler
and shall be easier to run and check.

Use Zope's access rule in the folder in order to set headers for OPTIONS
method too and also to avoid having ? in the backend URL.

Having WebPage_viewAsWeb in default skin selection break other sites
relying on default behavior of erp5_web.

This prevent getting DB read/write conflicts

Do not access form submission REQUEST from the listbox list method,
as it is rendered asynchronously in ERP5JS

This reverts commit 35b2c024c2b6fb33271d949b4529e1bf75e94585.

Allow edition in the new UI

This make everything slow as hell and prevent to quickly save.

Keep compatibility with existing officejs tests, by keeping the
data-i18n attributes, even if useless.

Chrome will deprecate appcache in the coming weeks.
As appcache has been dropped on Firefox, this change will improve the speed on Firefox.

The service worker only provide a cache for all ERP5JS gadgets.
ERP5JS will still be usable on browser without service worker API.

The list of files to cache is directly added inside the service worker
code, in order to be able to skip the usage of the fetch method (which
does not yet cover all browser HTTP usage).

This list is configurable on the web site level.
No need to change the service worker code directly.

The service worker will be updated as soon as the web site modification date changes.

End user does not need to reload its browser tab.
Only browsing ERP5JS will trigger the service worker update.

When a new update is found, ERP5JS will automatically reload itself if
there is no risk of losing user data input.

An empty appcache is kept, to allow migration of existing client to the
worker automatically.