Fix playlist_item_t.i_id vs input_item_t.i_id mess in HTTP interface. (Looks like this was new in 0.9.0. Having 2 differents integer ids, one being used to play and the other needed to delete the item is kind of awkward.)

Googleimage to use artist-tag and do url-encode (example taken from
http://www.redwiki.net/wiki/wiki.php/LUA/URLencode%B1%B8%C7%F6%C4ڵ%E5 )

Second try, show save meta button if user changes any input field, also
then set in_edit=true so playlist changes doesn't change meta-data what
to edit.

- Add rtcp boolean to emit RTCP SR

Edit mediainfo so you can edit meta-data even when playitem changes in
background. Also sets default to readonly, so user can't change meta if
he/she doesn't want to edit it. First try ;)

Patch by Ilkka Ollakka, modified by myself to rip-off extra spaces, to modify a constant one and not 4 times, and functions placement in the code.

Doesn't fix input memleaks (playlist.m:204-214)

Fix [21193]