Minor Starting from 6.0-HF20 (see NXP-17772) in SQLDirectoryFeature directories are deleted then rebuilt between test.
This is done for each registered directory not taking into account their type or status (i.e. read only).
This prevents from executing tests when several Directory types are used.
(also PlatformFeature includes SQLDirectoryFeature)
Customer thinks SQLDirectoryFeature should only deal with SQLDirectories that are not ReadOnly.
Provided pull request : https://github.com/nuxeo/nuxeo/pull/217
