Refactoring:
-removed duplicated code
-removed passing of username/password through all the modules
-logical order of the methods
-some optimizing and drying
-comments
New features:
-subcatalog link can be saved to the list of servers (eg: direct link to the catalog of books by an author)
-more book information can be fetched and shown (Book information)
-fixed access to the Standard library (by @KGKopli, closes#9372)
c36a2929ac