Update Smack to 4.0.0

[Flowdalic]

spring-ws needs to be upgraded to use Smack 4.0 before spring-integration needs to be upgraded in #1137

[artembilan]

@Flowdalic , thank you for contribution. I'm commenting here, because don't want to disturb @poutsma from SI PR.

I see changes to Spring WS are less, then to SI and I don't think that it will hurt to include it in point release of WS (2.2.1). It allows for SI 4.1 to be released independently of plans for WS 2.3.
@poutsma , WDYT?

[artembilan]

Can't SmackException and IOException be wrapped with XMPPException to avoid breaking changes for end-applications?

[Flowdalic]

Not sure if it's possible but I don't think that this is a good idea because in Smack 4 XMPPExceptions are only for errors defined in a XMPP related protocol.

[Flowdalic]

Please note that any version of Spring-ws that includes Smack 4 will break any version of spring integration that does not use Smack 4.

[artembilan]

will break any version of spring integration that does not use Smack 4.

It doesn't matter, because Spring Integration WS doesn't depend of Smack. We actually have an issue with versions only, if user wants to use SI-ws and SI-xmpp in the same app.

@Flowdalic, forget that versions issue - it is already our 'headache'.

In this PR I just want to have breaking changes as less as possible to allow end-users just upgrade Spring-WS and Smack. Actually the same is up to SI.

That's why we still need an input from @poutsma as a WS project lead.

[Flowdalic]

Ahh right, Smack is an optional dependency in spring-ws. So I guess I leave it to you to figure out the details. Feel free to ask if there is anything else. :)

[artembilan]

This one should be closed in favor of #48 .
Thank you @Flowdalic for the contribution anyway!

[gregturn]

I actually used this PR to write the other one. Salvaging the other was too difficult with all the master changes. Thanks!

[gregturn]

I plan to denote the commit here when completed.

[gregturn]

Resolved via 85c4832