TMDB APIv3: update API URLs and queries

remove obsolete API elements
add configuration API element. This contains url parts, e.g. for images,
that may be changed by TMDB.
add function to generate image URL according to given parameters

Signed-off-by: Marco Porsch <marco.porsch@etit.tu-chemnitz.de>
TMDB APIv3: update Settings View

update available API settings

Signed-off-by: Marco Porsch <marco.porsch@etit.tu-chemnitz.de>
TMDB APIv3: retrieve API configuration once after startup

also fix indentation
Note: possible race condition with image loading on Welcome View

Signed-off-by: Marco Porsch <marco.porsch@etit.tu-chemnitz.de>
TMDB APIv3: update Movie Genres View

use JSONListModel to fill ListView
update names of retrieved API objects

Signed-off-by: Marco Porsch <marco.porsch@etit.tu-chemnitz.de>
TMDB APIv3: update Movie Browse View

use JSONListModel to fill ListView
update names of retrieved API objects
implement dynamic multi-page list. Retrieve next page from API once user
scrolls to the end of the current list. Append list with retrieved objects.
TODO: visual user feedback for next-page loading

Signed-off-by: Marco Porsch <marco.porsch@etit.tu-chemnitz.de>
TMDB APIv3: update Search View

use JSONListModel to fill ListView
remove error state that has no counterpart in JSONListModel
implement dynamic multi-page list. Retrieve next page from API once user
scrolls to the end of the current list. Append list with retrieved objects.
TODO: visual user feedback for next-page loading

Signed-off-by: Marco Porsch <marco.porsch@etit.tu-chemnitz.de>
TMDB APIv3: update Movie View

update names of retrieved API objects
add Backdrop Gallery
add Alternative titles Column
implement Cast & Crew View and Poster & Backdrop Gallery the lazy man's way
using two completely separate models
pass complete person object to Person View
update Gallery and Previewer for new image retrieval using configuration API

Signed-off-by: Marco Porsch <marco.porsch@etit.tu-chemnitz.de>
TMDB APIv3: update Person View

update names of retrieved API objects
implement Cast & Crew Filmography the lazy man's way using two
completely separate models

Signed-off-by: Marco Porsch <marco.porsch@etit.tu-chemnitz.de>