Improve the deployment mechanism
The deployment mechanism permits to delay a bit the update:
- first you change the version (at this point the previous version is still used),
- then you run the script maintenance/update.php (with the new version),
- at the end of this run, the new version becomes globally available.
Because of this "caching" step, deleted wikis still appeared. This commits
- when the ‘deployments’ file is declared but nonexistant, it is created with the content of the ‘versions’ file -- even if this could only be a part of the whole farm if some wikis have their versions declared in the ‘variables’ files;
- the functions setVersion and updateVersion are partly re-written to be more readable.