* [JENKINS-6798] Redirect on HTTP >= 502 (502, 503, 504)

When Jenkins is behind a reverse proxy and is not available or
restarting, the reverse proxy will answer a HTTP 502 (because the upstream
doesn't answer).

* Add upper bound

* Hide password form fields by default

* Trying to bypass enforced autocompletion by just having a test field at first

Something like onfocus didn't work, you'd tab through form elements
and unless you filled in the user name, changing the form field to
password would cause it to autocomplete.

It looks like, at least in Mac/Firefox, going from plain text to password
in the 'oninput' event handler works. The plain text is revealed neither
with typing nor pasting.

* Update core/src/main/resources/lib/form/password.jelly
Co-Authored-By: Ndaniel-beck <daniel-beck@users.noreply.github.com>

* Use previously defined value

* Make new password form fields opt-out

* Add support for redacting form secrets in new password field

* Have a password value pre-set in Jelly

* Fix method

* Fix test by clicking on the button to change the password

* Forgot period separator between class and property name

Signed-off-by: Nolivier lamy <olamy@apache.org>

We use different suffixes for Hudson and Jenkins. I have found and fixed
following errors.

- Hudson'a -> Jenkins'e
- Hudson'da -> Jenkins'de
- Hudson'ı -> Jenkins'i
- Hudson'ın -> Jenkins'in
- Hudson'la -> Jenkins'le

Update the Plugin Manager Updates View with more Info about incompatible dependencies and change CSS classes (#4299)

* add information about incompatible plugin updates

* use alert-danger CSS class

* revert stripping whitespaces

* Update core/src/main/resources/hudson/PluginManager/_table.css to include a line brak at the end
Co-Authored-By: NOleg Nenashev <o.v.nenashev@gmail.com>

* use separate text for list of incompatible plugins

* restore and deprecate style.css

* make better use of caching

* [JENKINS-58296] Revert "[JENKINS-53462] Submit form on Firefox as well"

This reverts commit acc4eec6.
This change had been made in Jenkins to anticipate Firefox not dispatching
untrusted submit events anymore in v69, but this has actually been backed out.

See https://bugzilla.mozilla.org/show_bug.cgi?id=1370630

Since this change seems to have introduced a double-submission bug on forms
with inputs of type "file", reverting sounds like the next logical step.

* [JENKINS-58296] added comment about the Firefox case

* Remove browser-based metadata download

* Fix Javadoc, add TODO

* Further cleanup

* Remove leftover reference to DownloadService from UI

* License header and note of origin for DailyCheck

* Add Javadoc with note about the update frequency