Changes to integrate the websocket module as a full Qt Add-On module

Changes to integrate the websocket module as a full Qt Add-On module

- Changed project files to use Qt structure
- Moved existing sources into subdirectory, to make room for moduels
- Created a "import/qmlwebsocket" module skeleton (works, but needs to be extended)
- Modified examples to not use "include(.pri)", but use "QT += websocket"
- Added qml example skeleton (works, but no useful functionality yet)

Project can be build with:

$ qmake
$ make
$ make install

Module can be used in other projects with

QT += websockets

Change-Id: I2123026958b264670dbf8a978dee76edf5855806
Reviewed-by: Kurt Pattyn <pattyn.kurt@gmail.com>