[sysadmin] Fix backup scripts (demoInfo was not backed up!). Don't make incremental copies (delegated to sysadmin script). Update documentation.

[mcolom]

The backup is made from the copy of ipolDevel done every week, which contains correct (exported) database files. If the copy to Navy is done in a separate day of the week, it doesn't need to export again the databases. At this moment the first copy is done on Mondays and the copy to Navy on Thursdays.