#1251878: Cubicweb no longer crash for missing instance and data dir at create.
Those directory should be created by cubicweb now.
We may want to issue a warning if they are missing.
CSS Coding Standards--------------------(Draft, to be continued):Naming: camelCaseIndentation rules~~~~~~~~~~~~~~~~~- 2 espaces avant les propriétés- pas d'espace avant les ":", un espace après- 1 seul espace entre les différentes valeurs pour une même propriétéDocumentation~~~~~~~~~~~~~Please keep rules semantically linked grouped together, with a comment aboutwhat they are for.Recommendation~~~~~~~~~~~~~~- Try to use existing classes rather than introduce new ones- Keep things as simple as possible while in the framework- Think about later customization by application- Avoid introducing a new CSS file for a few lines of CSS, at least while the framework doesn't include packing functionalities