[Development] Common base class for all socket types

[d3fault]

"a common base class is an interesting idea. But it’s a moot point
since we have to maintain binary compatibility until Qt 5. So
QAbstractSocket cannot change. We’ll revisit the issue when Qt 5
development starts, but that’s a long way in the future". (
http://blog.qt.digia.com/blog/2008/02/22/qlocalserver-qlocalsocket/#comment-1820
)

"It won't happen for Qt 5. It's way too late for that". (
http://lists.qt-project.org/pipermail/development/2012-November/007746.html
)

d3fault