Use a ServletRequestAuthenticator to authenticate SiteMinder users

OF-1335 Part Two: Strip namespaces differently

Disable External Entities in plugin.xml

This checks to see if any occupant exists with
the same full jid, and if so treats this as a
clientOnlyJoin (ie, rejoin).

This commit grew a little larger than anticipated - my apologies for the reviewer. The original intend
for this was to allow changes in the java Keystore to be applied, without requiring a restart of Openfire.
This is what allows outside processes to update the Keystores - think Let's Encrypt - but could also be
useful for other purposes.

In the process of writing this code, I've found that a restart of the Connection Acceptor would still cause
all existing connections to be terminated. This is why a 'reload configuration' method was added.

I've found that the old Certificate Event Listener methods were unuseful. They were pretty detailled, but
all implementations used them in the same way: "reload everything". I've replaced those with one
'something changed' event. Also, the event listeners are no longer triggered in various places in the code.
Instead, the event listeners will now be triggered by the filesystem-based change of the keystore - the same
event that's used to reload configuration when Let's Encrypt updates pop up.

I've removed various bits of lengthy, unused code in the old CertificateManager (primarily code that
interacts directly with KeyStores, as that caused timing issues during the reload).

One functional change (that was marked as 'unsure why we do this' in code) is that after this commit, the
content of the identity store is no longer merged with the content of the trust store, while determining if
a particular end-entity certificate is to be trusted.

* OF-1418: Be less noisy with user not found.

* Fix line endings!

* Also do something similar with GroupNotFoundException

OF-1335: Don't strip namespaces everywhere.

Openfire prevents the need to re-scope XML (as described in RFC 6120 section 4.8.3) by
pre-emptively remove certain namespaces (such as 'jabber:client' and 'jabber:server').
It should not, however, remove these namespaces everywhere. This commit prevents such
removal in places other than the first and second level elements (typically: stream
and stanza elements).

I replaced the info for the old Community with the info for the new Discourse one and added a link to the Community under Resources.

OF-1412 Add automated setup support on first run

OF-1408 Show the cache expiry time on the caches page

OF-1409: Ensure that clearing the cache is audited.

OF-1410: Allow the openfire.bat file to be run from anywhere.

Also, edit the .editorconfig file so .bat files keep their CRLF endings.

Also remove unnecessary variable assignment

If <setup>true</setup> does not exist in openfire.xml (i.e. setup is not complete, and a block does exist called <autosetup> with a <run>true</run> property inside it, that looks like this:

```
    <autosetup>
        <run>true</run>

        <locale>en</locale>
        <xmpp>
            <domain>localhost</domain>
            <fqdn>localhost</fqdn>
        </xmpp>
        <encryption>
            <algorithm>AES</algorithm>
            <key>some-key</key>
        </encryption>
        <database>
            <mode>standard</mode>
            <defaultProvider>
                <driver>org.postgresql.Driver</driver>
                <serverURL>jdbc:postgresql://localhost:5432/a-database</serverURL>
                <username>a-database</username>
                <password>a-password</password>
            </defaultProvider>
        </database>
        <admin>
            <email>admin@example.com</email>
            <password>admin</password>
        </admin>
    </autosetup>
```

Then setup will be run on first launch, and the `<autosetup />` section will be deleted from openfire.xml

Fix OF-1159 - add database column to identify encryption status

* OF-1356 add section for Windows x86 to x64

* OF-1356 formatting fixes

* add missing </li>

Added Dockerfile

* related to OF-1383 work on java9 support
 * also updated setting to set min jre version to 1.7

* Moved detail text to under the field label i.e. left of the field.
* the add user/group text box has been moved to the bottom row of the
  repective table, and table headings have been changed.
* Fixed bug where blank properties were causing empty jids to be populated
  for sysadmins and allowedToCreate on the PubSubModule.
* Fixed bug where options were removed from the forms after users/groups
  were added (options were not being transfered onto the new form).

* Fixed Row numbers on node summary table OF-1386
* improved logging of affiliation changes
* updated affiliation update version to use global update string