This fixes issue there on android in XHTMLExtension bodys contained "null" instead of actual xhtml tags
This happened due to difference in XPP implementation in KXmlPullParser (on Android) MXParser (in other cases)
This fix replaces usage of getText method of XPP with restoration of xhtml tags using XPP api.
- Fix "packet.Time is not thread-safe" (SMACK-543)
- Update packet.Time to XEP-0202
Add SDM.supportsFeature(), since this is a pattern that repeats over and
over again in Smack. Also add abstract Manager class, that takes care of
the weak reference to Connection, as this is also a repeating pattern in
Smack.