API changes, most recent first:
+2016-xx-xx - xxxxxxx - lavu 55.39.100 - hwcontext_vaapi.h
+ Add AV_VAAPI_DRIVER_QUIRK_ATTRIB_MEMTYPE.
+
+2016-xx-xx - xxxxxxx - lavu 55.38.100 - hwcontext_vaapi.h
+ Add driver quirks field to VAAPI-specific hwdevice and enum with
+ members AV_VAAPI_DRIVER_QUIRK_* to represent its values.
+
2016-11-10 - xxxxxxx - lavu 55.36.100 - pixfmt.h
Add AV_PIX_FMT_GRAY12(LE/BE).