signal messageReceived moved to base class

New Qt5 Signals & Slots ( see :
http://qt-project.org/doc/qt-5.0/qtcore/signalsandslots.html ) need this
signal only in the base class.

This way next example can be done :
nzmqt::ZMQContext* context = nzmqt::createDefaultContext( this );
nzmqt::ZMQSocket* input = context->createSocket(
nzmqt::ZMQSocket::TYP_SUB, this );
input->subscribeTo( "topic" );
QObject::connect( input, &nzmqt::ZMQSocket::messageReceived, &myObject,
&myObject::myMagic );
//or even lambda functions can be used
QObject::connect( input, &nzmqt::ZMQSocket::messageReceived, [=](){
doMagic(); } );
Merge pull request #13 from dgtBartS/master

New Qt5 Signals & Slots functionality added
changelog,gh-13: Add entry.
Merge commit 'b0716863719a7b3bfe06cb27e01b1b201bfed165'

* commit 'b0716863719a7b3bfe06cb27e01b1b201bfed165':
  changelog,gh-13: Add entry.
Merge branch 'master' into branch-2.x

# By Jonny Dee (1) and dgtBartS (1)
* master:
  changelog,gh-13: Add entry.
  signal messageReceived moved to base class