[tumblr] Replaced test URL for HD video as old one lead to 404
[tumblr] Don't make assumptions about video resolution, cleaner handling of no HD version available
[tumblr] Removed extraneous resolution key in HD video tests
Now the semantic of this function is identical to
shutil.get_terminal_size() in Python 3.3+. The new behavior also
corresponds to the old get_term_width(), which is removed in
003c69a84b