Don't show other people's public collections
Merge branch 'zas-info_dialog'
small stylistic changes
Introduce CoverArtDownloader class

coverart.py cleanup on the way
CoverArtDownloader: step 2
CoverArtDownloader: step 3
Pass CoverArtDownloader object instead of try_list
Store album, release, metadata in CoverArtDownloader object
_fill_try_list(): drop album parameter, use cover_art_downloader property instead
_fill_try_list(): drop release parameter
_walk_try_list(): drop album, metadata, release parameters
_coverart_downloaded(): drop album, metadata, release parameters
_caa_json_downloaded(): drop album, metadata, release parameters
Move CoverArtDownloader declaration on top of the file
Move COVERART_SITES to class CoverArtDownloader
Move AMAZON_SERVER to class CoverArtDownloader
Move AMAZON_IMAGE_PATH to class CoverArtDownloader
Move AMAZON_ASIN_URL_REGEX to class CoverArtDownloader
Move _CAA_THUMBNAIL_SIZE_MAP to class CoverArtDownloader
_try_list_append_image_url() becomes a CoverArtDownloader method