This allows us to exploid Java 8 streams and Java 5 for-each
loops. The returned Collections are usually unmodifiable. We decided
against returning Iterable because this would mean determining the
size in O(n) compared to Collection.size() which is often faster
(e.g. O(1)).
- 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.
Change all \r\n into unix style newlines. Add missing newlines at the
end of a file and activate the newline checkstyle module, that enforces
'\n' as newline and a newline at the end of every file.