mpv: add recipe and patch for version 0.8.2

* currently crashes while trying to display video due to bugs in SDL

media-video/mpv/patches/mpv_x86-0.8.2.patchset

@@ -0,0 +1,42 @@
+From 5aab1c265b3d6d0339453bce590707fb2ba25a3d Mon Sep 17 00:00:00 2001
+From: Sergei Reznikov <diver@gelios.net>
+Date: Mon, 16 Mar 2015 20:44:40 +0300
+Subject: Haiku: comment out subprocess functions
+
+* We lack spawn.h header so we can't use posix-spawn from subprocess-posix.c
+* subprocess-haiku.c probably needs to be implemented
+
+diff --git a/player/command.c b/player/command.c
+index b89f7c0..71058c3 100644
+--- a/player/command.c
++++ b/player/command.c
+@@ -4014,7 +4014,7 @@ static void overlay_uninit(struct MPContext *mpctx)
+         overlay_remove(mpctx, id);
+     osd_set_external2(mpctx->osd, NULL);
+ }
+-
++/*
+ struct subprocess_args {
+     struct mp_log *log;
+     char **args;
+@@ -4047,7 +4047,7 @@ static void subprocess_detached(struct mp_log *log, char **args)
+     if (pthread_create(&thread, NULL, run_subprocess, p))
+         talloc_free(p);
+ }
+-
++*/
+ struct cycle_counter {
+     char **args;
+     int counter;
+@@ -4631,7 +4631,7 @@ int run_command(MPContext *mpctx, mp_cmd_t *cmd)
+         char *args[MP_CMD_MAX_ARGS + 1] = {0};
+         for (int n = 0; n < cmd->nargs; n++)
+             args[n] = cmd->args[n].v.s;
+-        subprocess_detached(mpctx->log, args);
++//        subprocess_detached(mpctx->log, args);
+         break;
+     }
+ 
+-- 
+2.2.2
+