[Qgis-developer] WIP: QGIS Server refactoring

[René-Luc Dhont]

Hi devs,

We (David Marteau and I) will start the QGIS Server refactoring.

The first step for us is to develop the *service register* like 
described in the QEP: QGIS server code refactoring for QGIS 3.0 
https://github.com/qgis/QGIS-Enhancement-Proposals/issues/74

To keep the developement open, we proposed to use a github repository to 
centralize *Pull Request* and development strictly on QGIS Server with a 
dedicated branch https://github.com/3liz/QGIS/tree/master_qgis_server
We proposed to do so to have the possibility to broke the code but we 
will continue to merge master in it during the dev.
We will open the right to other QGIS Server developers and be proud to 
review Pull Request.

Our goal is to keep the functionalities, simplify the code and add 
modularity; to have something more maintainable, robust and expendable.

Regards,
René-Luc D'Hont
3Liz