Add release note for v6.12.0

NEWS

@@ -1,6 +1,82 @@
 MLT Release Notes
 -----------------
 
+Version 6.12.0 - November 26, 2018
+
+This version has many important fixes plus a few new filters and support for
+encoding using VA-API.
+
+Framework
+  * Changed buffer property to be mutable and adaptive to speed property in
+    mlt_consumer.
+  * Changed macOS RELOCATABLE build to use standard app bundle layout:
+    - lib/mlt      -> ../PlugIns/mlt
+    - lib/frei0r-1 -> ../PlugIns/frei0r-1
+    - lib/ladspa   -> ../PlugIns/ladspa
+    - share/mlt    -> ../Resources/mlt
+    - share/movit  -> ../Resources/movit
+  * Fixed a_track of transitions matching deleted track in
+    mlt_tractor_remove_track().
+  * Fixed multi-thread race crash in mlt_properties_clear().
+  * Fixed possiblle null pointer crash in mlt_property_get_rect() and
+    mlt_property_get_time().
+  * Fixed non-animated strings containing ';' or '=' in mlt_animation_parse().
+  * Fixed crash in clear_property() with mlt_animation.
+
+Modules
+  * Added a generic text filter to the plus module.
+  * Added a timer filter to the plus module.
+  * Added audio timeout handling to sdl2 consumers.
+  * Added spot_remove filter to the plus module.
+  * Added dds, ico, and webp filename extensions for qimage producer.
+  * Added support for color_range property in avformat consumer:
+    "pc" or "jpeg" for full range, otherwise limited range.
+  * Added a window property to the audiowaveform filter.
+  * Added MM:SS.SS to the timer filter.
+  * Added query string param "multi" to the xml producer to force using the
+    multi consumer.
+  * Improved WebP image support in avformat producer.
+  * Integrated hwupload filter in avformat consumer if using VAAPI codec.
+  * Changed count producer to use pango if qtext not available.
+  * Changed qt moduled to not call XInitThreads()
+  * Changed color producer to only set alpha on frame if rgb24a requested or
+    not opaque.
+  * Changed the xml producer to pass quality and performance parameters to the
+    multi consumer.
+  * Fixed sdl2_audio distortion (regression in v6.10.0).
+  * Fixed dynamictext filter to not error on empty text.
+  * Fixed dynamictext aliased (regression in v6.10.0).
+  * Fixed qimage outputs premultiplied if scaled internally.
+  * Fixed crash in cbrts consumer if running property was never set.
+  * Fixed rendering edges of some typefaces in qtext producer.
+  * Fixed qimage fails to load with wrong filename extension.
+  * Fixed affine dark right and bottom edge artifacts regression in (v6.10.0).
+  * Fixed support for vp8 and vp9 with alpha channel in avformat producer.
+  * Fixed interpolation mode selection in qimage producer.
+  * Fixed crash in qimage with alpha channel.
+  * Fixed some AAC MP4 files start playing from middle in avformat producer.
+  * Fixed crash in avfilter if initialization fails.
+  * Fixed crash in mix when frame rate is very low.
+  * Fixed crash on missing luma file in composite transition.
+  * Fixed A/V sync on some files in avformat producer.
+  * Fixed seeking on audio filter with album art in avformat producer.
+  * Fixed colorspace conversion in avformat consumer.
+
+Other
+  * Added more avformat consumer presets:
+    - alpha/Quicktime Animation
+    - alpha/vp8
+    - alpha/vp9
+    - alpha/Ut Video
+    - lossless/Ut Video
+  * Added square video profiles:
+    - square_1080p_30
+    - square_1080p_60
+  * Added support for nodejs to the swig bindings.
+  * Changed configure script to require opencv module be explicitly enabled.
+  * Numerous spelling fixes in source code and comments thanks to codespell.
+
+
 Version 6.10.0 - July 2, 2018
 
 This version fixes bugs and supports serializing animation keyframes with a