Introduced parameters to printAsJson method so the list of books can be sorted and filtered.
Added path allbooks to LibraryService to get a list of all books as json.
Always return a author even if she doesn't exist in the library.
Converted author.dat to author.json
Adds link to books.
Renamed MyHttpClient.
some cleanup.
Introduced some variables for patterns and a constant for unknown links.
Moved getNewBooks to BookShelf.