Update currentIndex() to return only indices actually in book.  Page number box uses currentIndex()
Update currentIndex() to return only indices actually in book.  Page number box uses currentIndex()

garyrh/bookreader,openlibrary/bookreader,gootdude/bookreader,garyrh/bookreader,brisandbeans/bookreader,niksu/bookreader,Islandora/internet_archive_bookreader,nikolas/bookreader,brisandbeans/bookreader,Islandora/internet_archive_bookreader,internetarchive/bookreader,yankl/bookreader,niksu/bookreader,garyrh/bookreader,Islandora/internet_archive_bookreader,garyrh/bookreader,brisandbeans/bookreader,brisandbeans/bookreader,gootdude/bookreader,yankl/bookreader,garyrh/bookreader,Islandora/internet_archive_bookreader,brisandbeans/bookreader,gootdude/bookreader,Islandora/internet_archive_bookreader,openlibrary/bookreader,yankl/bookreader,gootdude/bookreader,yankl/bookreader,openlibrary/bookreader,niksu/bookreader,yankl/bookreader,nikolas/bookreader,openlibrary/bookreader,niksu/bookreader,internetarchive/bookreader,niksu/bookreader,openlibrary/bookreader