This is a complete redesign of what was previously
XmppNioTcpConnection. The new architecture allows to extend an XMPP
client to server (c2s) connection with new transport bindings and
other extensions.
and rename documentation links from .html to .md, since
markdown-gradle-plugin will now automatically transfer the links .md to
.html.
Now users can broswe the documentation in their markdown form (e.g. via
github) and via html.
Also add a symlink from README.md to index.md in documentation/.
