GitLab

#1397 Delete temporary Yaml file and incorporate new macos jobs in the usual one. Tags have been added to 'specialize' mac runners in order to speed up jobs.

#1397 Deactivate tests in the dummy Yaml, and try to deactivate warnings for older versions of macOS.

#1396 Fix three warnings (one more elegantly than previously where the warning was neutralized locally).

#1396 Remove an unneeded include (which was moreover triggering a warning as it was in experimental directory).

#1360 - #1393 Add the guideline to use macOS machine (and provide Yaml to skip it if no credentials to Nostromo). Add the part explaining how to set up Yaml to use in gitlab.

#1360 Fix syntax in Yaml: |& doesn't work with the bash used in macOS  (see https://stackoverflow.com/questions/20553916/syntax-error-near-unexpected-token-using).

#1394 Add explicitly in SourceList.cmake files that that are generated files that should not be edited manually.

#1393 Remove the VM directory in documentation: new way with Docker executor doesn't need to do such a bookkeeping.