OF-1004: Apply i18n to admin console

Fix some javadoc warnings

OF-821: Count occupants by nickname

OF-1034 Check for existing sessions properly

Returns the count of nicknames rather than the number of connections
(full JIDs), which will now also match the list of occupants.

solve the memory leak problems which is caused by add LocalMUCRoom ob…

OF-821: Prevent duplicates for MUC item query

Drop unnecessary null check.

Corrects issue with multiple JIDs sharing a nickname (masquerading)

Replaced the 'set this var with this translation' definition for
a functional equivalent but easier-on-the-eyes definition.

Fix implementation bug for XEP0049.

OF-1033: Should use the correct status code.

OF-1029: Allow web.xml override via overlay

OF-1033: Users should be notified of MUC service shutdown

Fix implementation bug for XEP0049. The comment in Line 105: "If the name and namespace of the element matches another" is correct, but the implementation is wrong, it checks "username and namespace" rather than "name and namespace".

Cleanup websocket plugin

This commit notifies all users that are in a MUC on the local server node of
a shut down of the service. The notification conforms to XEP-0045.

In order to prevent a prolonged shut down, this commit:
- ensures that a shutdown routine is executed just once (instead of for each
  type of interface being shut down: module,component and listener)
- the presence stanza that is sent is constructed using in-memory objects
  only (no database lookups)
- all notification occurs in a thread pool, which will concurrently process
  them, but will terminate forcibly after a certain amount of time.

Update dependencies and documentation to prep for pending Openfire 4.0
release.

OF-1028 Stream Management refactoring

Instead of rerequesting ack for every unack'ed stanza over the
threshold, do this only for every few stanzas. This prevents a storm
of ack-requests when data is transmitted to the client faster than it
can respond.

When a peer refuses to ack data, we should not keep it in memory
indefinately. This commit introduces a configurable upper bound,
and when reached causes the queue to be cleared (dropped silently)
while disabling the functionality for that connection.

The peer might send unsollicited acks. Instead of requesting ack after every
so many stanzas that we send out, only request ack if we have unack'ed stanzas.

This commit fixes an overflow issue.

To safely determine what stanza has and has not been ack'ed by the peer,
store the current value of 'x' with each stanza that's kept. This also
allows for proper handling when the peer rolls over X (at x=2^32).

Previous commits have applied enough refactoring that it is now no
longer needed to expose internal state. This saves on complexity and
potential concurrency issues.

The 'enabled' field is unneeded - the presence of a namespace also
indicates if SM is enabled. Reduces code, saves a little on memory.

By moving the processing of Stream Management elements into the
StreamManager implementation, duplicated code can be removed.

To reduce the chance of lock contention, locks should only be put
in effect when the code accesses data that is sensitive to concurrent
access.

Prevent exposing access to a field that we're careful to modify
under lock. Again, a defensive copy is a suitable alternative,
but seems unneeded.

Do not expose the collection of packets that our implementation
modifies only under a mutex (alternatively, we could return a
defensive copy instead, but there does not seem to be a need
to expose the collection in the first place).