Update README.md's ChatManager example to new API
Refactoring: All connection classes begin with XMPP now

This commit renames classes as follows:
 * TCPConnection --> XMPPTCPConnection
 * BOSHConnection --> XMPPBOSHConnection

There are two reasons for this rename. First, it is there to indicate
that the classes actually _are_ XMPP connections, using different
transport mechanisms. Second, it makes auto-completion in IDEs easier,
the developer can type XMPP<complete> and choose the right backend.
VCardProvider should treat tel code element optional

SMACK-555
Remove star imports in VCardProvider
Return Collections (or sublcasses) instead of Iterators

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)).
Make ConnectionConfugration getters public

No need to keep them package-private. SMACK-556
Add FromMode regarding 'from' attribute of outgoing stanzas

XMPP Servers should ignore the 'from' attribute of outgoing
stanzas. Makes the behavior how Smack populates the 'from' attribute of
outgoing stanzas configurable. Fixes SMACK-547
Return List instead of Collection where appropriate
Javadoc fixes

- Add hint to reconnection configuration
- s/connection.getChatManager/ChatManager.getInstanceFor(connection)
- typos
Bump jbosh to 0.8.0
Provide a MUC method to create *or* join a room

MulitUserChat.create() will throw an SmackException if the MUC service
does not return a 201 status when entering a room. Some MUC
implementations don't return the 201 status but instead behave like
the room already existed.

If the user doesn't care about the room beeing locked until the
initial configuration has been send, he can now use the new
MutliUserChat.createOrJoin(String) method.

Also remove some duplicate code by creating the private enter() method.

Fixes SMACK-557
Move gradle signing code out of allprojects

because it caused asking for the key passphrase multiple times, i.e. for
every subproject.
Make gradle use the local maven cache
Change keyringfile example to real file

I'm always using the file and forget to s/foo/flo/
Smack 4.0.0-rc1
Smack 4.0.0-rc2-SNAPSHOT
Fix typo in Roster.java: s/iss/is/
Fix PrivateDataManager getInstanceFor() always returns null
callConnectionAuthenticatedListener() should call authenticated()

not connected().
Improve proceedTLSReceived() documentation