switched InventoryView to zebra_form, bugfixes, code may still not be
usable with this commit -> global cleanup and tests need to be done
removed quickform2 completely, tested functionality and cleanup; the
code works again with this commit
code cleanup: removed anything pointing to old "rights" system
added usersetting to change username and email address; added demo mode
and checks against it
created File and FileView classes, created file caching for pdfs,
switched toPdf methods and listings to new File class, small bugfixes