net-libs/libvncserver: Add a bunch of upstream fixes
* fix CVE-2018-20750 (the fix for CVE-2018-15127 was incomplete)
* fix CVE-2019-15681
* fix libdir in pkgconfig files
* fix regression in Tight/Raw decoding
Bug: https://bugs.gentoo.org/699036
Closes: https://bugs.gentoo.org/676942
Closes: https://bugs.gentoo.org/691848
Package-Manager: Portage-2.3.76, Repoman-2.3.16
Signed-off-by: Alexander Tsoy <alexander@tsoy.me>
Closes: https://github.com/gentoo/gentoo/pull/13509
Signed-off-by: Joonas Niilola <juippis@gentoo.org>