don't access database if not set up yet

fixes fatal error when getting maxAssetsTime during installation
remove unintentionally copied file
add default value for uplodas folder

makes sense to set this as default instead of none
remove unused code
remove methods from public interface that are nowhere called

previously used in import afair
refactor clearCache into type classes

- much cleaner code
- easier to get progress
- easier to extend
add maintenance controller for clearing cache
refactor getDoneNames into public method
first version of script to execute updates from browser
fix typo
first version of an update downloader
fix typo in classname
fix update-downloader
take configured include_path to new kwf-lib