improve user's doc style
    add some explanation about the code structure in the main doxygen
    fix coverage in analysis sonarqube
    add a release job to automatize release publication
    change the cdash server to my.cdash.org which is more recent and reactive than cdash.inria.fr
    fix the version number, dates and authors in headers to prepare the release 0.9.2

we really need to remove cblas/lapacke headers to avoid the inclusion in .c files, we get them back after static analysis