Updated support for HTTP over XMPP (XEP-0332)

Updated Base64BinaryChunk packet and provider to support latest
version of specification (0.3):
- added support for new nr attribute.
SLF4J Smack Debugging Logger
Wait for Socks5TestProxy initialization

to prevent

org.jivesoftware.smackx.bytestreams.socks5.Socks5ClientForInitiatorTest
  > shouldSuccessfullyEstablishConnectionAndActivateSocks5Proxy
    FAILED
    java.lang.NullPointerException at Socks5ClientForInitiatorTest.java:292
Add SASL PLAIN implementation to smackk-sasl-provided