Fixes OF-1308

OF-1350 MUC passwords

* OF-1343 added comments about changes in 4.1.5

* OF-1343 a note about new service behavior

The static web content handler is allowed to be null (when there's no static content to be served). In such case, the null-handler shouldn't be loaded in Jetty (which will throws nullpointers).

Various plugin-related improvements.

EditorConfig helps developers define and maintain consistent coding styles between different editors and IDEs.

* OF-546: UserImportExport plugin should have admin console when built with Maven.

* OF-1355: UserImportExport should not fail on missing optional config.

A new Openfire plugin, that bundles the third-party Candy web client.

A new Openfire plugin, that bundles the third party 'inVerse' web client.

'max' implies to specify a server version that still supports the plugin, while typically, one would like to specify the first version in which support was dropped. That version should thus be 'exclusive'.

XMPP defines two configuration fields for password-protecting a room:
- one that defines if the room is password protected.
- another one that defines the password.

Openfire, internally, only stores the password, if password-protection is required.

Some clients send only a password, without explicitly defining the password-protection boolean. In such cases, Openfire should be somewhat flexible, and process the configuration form as intended by the user.

This commit started with the intention of adding a maxServerVersion attribute for plugins, but resulted in a partial rewrite. Changes:
- Removed the License enumeration - now, a simple string is used.
- Split off the admin console page that shows the content of readme and changelog files to a dedicated page, instead of plugin-admin.jsp
- Better define the difference between the plugin (human readable) name ("Avatar Resizer") and its canonical name ("avatarresizer")
- The admin console now shows plugins that have been downloaded/installed, but cannot be loaded. Where possible, an update is suggested.
- Support for maxServerVersion - plugins can now define a version of Openfire in which they will no longer load.

* OF-1342 Remove "Run Openfire" from the final step of the installer. Changed to "Start Openfire Service"

* OF-1342 Remove "Run Openfire" from the final step of the installer. Changed to "Start Openfire Service"

* OF-1349 Create separate Windows installer with and without JRE

This commit fixes a runtime problem caused by SortedSet usage with providers that are not Comparable. By using a different Set implementation, iteration order is predictable, without there being a need for providers being Comparable.

This commit adds some UX improvements to the 'edit group' page on the admin console.

Hopefully addressses UAC issues. Installs services on windows at install. Replaces launcher with starting service and launching web browser.  Adds option to create x64 installer for windows.

Attempt to address UAC issues with Windows. Installs services on windows at inst…

Hopefully addressses UAC issues. Installs services on windows at install. Replaces launcher with starting service and launching web browser.  Adds option to create x64 installer for windows.

OF-1336: Introduce UserPropertyProvider

By using a concatination of an interned string with another string, the resulting string will not be interned itself - making for non-functional lock.

These changes should be backwards compatible.

This commit adds a new feature to Openfire, that allows one to store user properties in an external system. This is quite similar to concepts like UserProvider, AuthProvider, GroupProvider, and so on.

The default behavior, moved from the User class to DefaultUserPropertyProvider, continues to use the ofUserProp database table. Provider implementations matching those of other types of providers have been added.

This commit allows a plugin.xml to use a reference to data defined in the pom.xml. This reduces duplicate data.

For instance, in plugin.xml, one could now define the version number by referring to the version number of the
maven artifact:

  <version>${project.version}</version>

Note that plugin.xml files that are processed using the old Apache Ant based build, will not be processed correctly.