Update Smack to 4.0.5

Smack versions older then 4.0.2 have known security vulnerabilities:
- CVE-2104-0363
- CVE-2014-0364
- CVE-2014-5075

Note that Smack 4 throws more exceptions compared to previous versions,
and since openhab still targets Java6, we have some code duplication in
the catch blocks since we can't use try/multi-catch (which is a Java7
language feature).
Avoid resource leaks in XMPP.sendXMPP()