* followup on 748a78c3c7
* fix return type of criteria filter callbacks (mostly in case of faulty input)
* spread the criteria var into criteria filter callbacks
* some magic numbers to constants and type declarations for params/return types
* fixed several deprecation notices and warnings from MySQL8, most notably:
- SQL_CALC_FOUND_ROWS: stopped using DBSimple::selectPage and query 'SELECT COUNT(*) ...' separately where needed
- ON DUPLICATE KEY UPDATE ... VALUES(): use row alias for new values instead of VALUES function
- boolean shorthands to long form (&& -> AND, etc)
* convert configuration from list of constants to object
* fixes config changes not applying on cli whithout closing and reopening again
* config variables are no longer embedded in localization text
* fixed misc issues Intellisense was nice enough to highlight.
* mostly deprecated usage of uninitialized parameters
* class GenericPage still needs a long, hard look and a refactor
* fixed wrong indizes for gem color picker in locale 3 (deDE)
* fixed interpretation of filter enums. Some are providing their value directly, others have an intermediate key.
* createSQLForCriterium is no longer abstract. (was implemented in exactly the same way everywhere)
* erronous criteria are now logged and discarded entirely)
