This reverts commit 97f83156.

Move cryptography specific functions into their own file, together with
functions downloading public key / signatures
Factorize common code for generating signatures (hash_sha1_from_*)
Remove unused update_WaitDownload (was OSX specific)

media_list_player: Make sure we'll correctly play next item, instead of setting the item but not playing it.

Add a test for correct item queuing as well.

Win7: add support for the taskbar's "oh, look, it's shiny" buttons. We need prettier buttons, and in some cases, the play/pause button's picture isn't updated.

psz_object_name can only be read from the thread calling module_need()
for the current object. As an alternative, module_need() would have to
be called before vlc_object_attach(), which would break var_CreateGet*.

Fix BDA compilation for Win64

Work done by NightStrike

and the pointer is never modified).

This reverts "test: Disable test_media_list_player as it deadlocks."

This reverts commit 3403c427.