itunes playlist first commit (#5860)

Added playlist feature for the itunes command: 
if a variable is passed and is valid - will play the playlist
if a variable is passed and is invalid(no such playlist) - will stop all playing
if no variable is passed will print all playlists available on the host

plugins/osx/osx.plugin.zsh

@@ -184,6 +184,7 @@ function vncviewer() {
 # iTunes control function
 function itunes() {
 	local opt=$1
+	local playlist=$2
 	shift
 	case "$opt" in
 		launch|play|pause|stop|rewind|resume|quit)
@@ -200,6 +201,19 @@ function itunes() {
 		vol)
 			opt="set sound volume to $1" #$1 Due to the shift
 			;;
+		playlist)
+		# Inspired by: https://gist.github.com/nakajijapan/ac8b45371064ae98ea7f
+if [[ ! -z "$playlist" ]]; then
+                    		osascript -e 'tell application "iTunes"' -e "set new_playlist to \"$playlist\" as string" -e "play playlist new_playlist" -e "end tell" 2>/dev/null;
+				if [[ $? -eq 0 ]]; then
+					opt="play"
+				else
+					opt="stop"
+				fi	
+                  else
+                    opt="set allPlaylists to (get name of every playlist)"
+                  fi
+                ;;
 		playing|status)
 			local state=`osascript -e 'tell application "iTunes" to player state as string'`
 			if [[ "$state" = "playing" ]]; then
@@ -250,6 +264,7 @@ EOF
 			echo "\tshuf|shuffle [on|off|toggle]\tSet shuffled playback. Default: toggle. Note: toggle doesn't support the MiniPlayer."
 			echo "\tvol\tSet the volume, takes an argument from 0 to 100"
 			echo "\tplaying|status\tShow what song is currently playing in iTunes."
+			echo "\tplaylist [playlist name]\t Play specific playlist"
 			echo "\thelp\tshow this message and exit"
 			return 0
 			;;