Fix use of ISC license

The license text refers a "above copyright notice", so I guess it'd be
good to actually provide such a notice.

Add the license to some files that were missing it (since in theory, our
Copyright file says that such files are LGPL by default).

Remove the questionable remarks about the license in the client API.

4 files changed, 15 insertions, 31 deletions

diff --git a/libmpv/client.h b/libmpv/client.h
index c6d67094d3..ff73a03eea 100644
--- a/libmpv/client.h
+++ b/libmpv/client.h
@@ -1,4 +1,6 @@
-/* Permission to use, copy, modify, and/or distribute this software for any
+/* Copyright (C) 2017 the mpv developers
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
  * purpose with or without fee is hereby granted, provided that the above
  * copyright notice and this permission notice appear in all copies.
  *
@@ -12,13 +14,9 @@
  */
 
 /*
- * Note: the client API is licensed under ISC (see above) to ease
- * interoperability with other licenses. But keep in mind that the
- * mpv core is still mostly GPLv2+. It's up to lawyers to decide
- * whether applications using this API are affected by the GPL.
- * One argument against this is that proprietary applications
- * using mplayer in slave mode is apparently tolerated, and this
- * API is basically equivalent to slave mode.
+ * Note: the client API is licensed under ISC (see above) to enable
+ * other wrappers outside of mpv. But keep in mind that the
+ * mpv core is still mostly GPLv2+.
  */
 
 #ifndef MPV_CLIENT_API_H_
diff --git a/libmpv/opengl_cb.h b/libmpv/opengl_cb.h
index fff76526a4..c77665d895 100644
--- a/libmpv/opengl_cb.h
+++ b/libmpv/opengl_cb.h
@@ -1,4 +1,6 @@
-/* Permission to use, copy, modify, and/or distribute this software for any
+/* Copyright (C) 2017 the mpv developers
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
  * purpose with or without fee is hereby granted, provided that the above
  * copyright notice and this permission notice appear in all copies.
  *
@@ -11,16 +13,6 @@
  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
 
-/*
- * Note: the client API is licensed under ISC (see above) to ease
- * interoperability with other licenses. But keep in mind that the
- * mpv core is still mostly GPLv2+. It's up to lawyers to decide
- * whether applications using this API are affected by the GPL.
- * One argument against this is that proprietary applications
- * using mplayer in slave mode is apparently tolerated, and this
- * API is basically equivalent to slave mode.
- */
-
 #ifndef MPV_CLIENT_API_OPENGL_CB_H_
 #define MPV_CLIENT_API_OPENGL_CB_H_
 
diff --git a/libmpv/qthelper.hpp b/libmpv/qthelper.hpp
index 8615d0f84b..f91aa15ea4 100644
--- a/libmpv/qthelper.hpp
+++ b/libmpv/qthelper.hpp
@@ -1,4 +1,6 @@
-/* Permission to use, copy, modify, and/or distribute this software for any
+/* Copyright (C) 2017 the mpv developers
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
  * purpose with or without fee is hereby granted, provided that the above
  * copyright notice and this permission notice appear in all copies.
  *
diff --git a/libmpv/stream_cb.h b/libmpv/stream_cb.h
index 1f1bf2333c..01de4700b2 100644
--- a/libmpv/stream_cb.h
+++ b/libmpv/stream_cb.h
@@ -1,4 +1,6 @@
-/* Permission to use, copy, modify, and/or distribute this software for any
+/* Copyright (C) 2017 the mpv developers
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
  * purpose with or without fee is hereby granted, provided that the above
  * copyright notice and this permission notice appear in all copies.
  *
@@ -11,16 +13,6 @@
  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
 
-/*
- * Note: the client API is licensed under ISC (see above) to ease
- * interoperability with other licenses. But keep in mind that the
- * mpv core is still mostly GPLv2+. It's up to lawyers to decide
- * whether applications using this API are affected by the GPL.
- * One argument against this is that proprietary applications
- * using mplayer in slave mode is apparently tolerated, and this
- * API is basically equivalent to slave mode.
- */
-
 #ifndef MPV_CLIENT_API_STREAM_CB_H_
 #define MPV_CLIENT_API_STREAM_CB_H_