improves testability
adds a better configuration system, which is backward compatible
added support for internationalization
fixed bug when slashes are used in bibtex keys
refactoring
refactoring
fixed bug when @String are removed
implements  &search=key1|key2|key3  or  &search=key1,key2,key3 for emulating \cite{key1,key2,key3} (feature request by Mateusz)