libass: upgrade 0.16.0 -> 0.17.0

Detailed Changes:
==================
- Fix various parts relating to automatic linebreaking
- Fix rendering when hinting was enabled and fontsizes or scales are zero
- Switch build to a non-recursive setup for improved parallelism
- Improve quality of SSA Effects movement
- Further documentation improvements
- Completely invalid Events are now discarded during parsing
- Introduction of LayoutRes{X,Y} script headers
- New AlphaLevel style override to set all alpha values while keeping the color
- Add ASS_FEATURE_WRAP_UNICODE to allow automatic linebreaks in accordance with
  the Unicode line breaking algorithm instead of ASS' much stricter breaking
  rules. For the feature to be available at runtime, libass must be linked
  against the new optional dependency libunibreak.
- Improve VSFilter compatibility:

Signed-off-by: Wang Mingyu <wangmy@fujitsu.com>
Signed-off-by: Khem Raj <raj.khem@gmail.com>

meta-oe/recipes-multimedia/libass/libass_0.17.0.bb

@@ -8,7 +8,7 @@ LIC_FILES_CHKSUM = "file://COPYING;md5=a42532a0684420bdb15556c3cdd49a75"
 DEPENDS = "fontconfig freetype fribidi harfbuzz"
 
 SRC_URI = "git://github.com/libass/libass.git;protocol=https;branch=master"
-SRCREV = "1af6240c5d1e499326146e0b88c987e626b13c23"
+SRCREV = "bef4b43ef1882b77f789f611d9cd24271ccdd65b"
 S = "${WORKDIR}/git"
 
 inherit autotools pkgconfig