spice: security bump to version 0.14.1

spice: security bump to version 0.14.1

Fixes CVE-2018-10873: A vulnerability was discovered in SPICE before version
0.14.1 where the generated code used for demarshalling messages lacked
sufficient bounds checks.  A malicious client or server, after
authentication, could send specially crafted messages to its peer which
would result in a crash or, potentially, other impacts.

Drop patches as they are now upstream.

Add host-pkgconf as the configure script uses pkg-config.  Drop removed
--disable-automated-tests configure flag.

Add optional opus support, as that is now supported and needs to be
explicitly disabled to not use.  Explicitly disable optional gstreamer
support for now as the dependency tree is fairly complicated.

Signed-off-by: Peter Korsgaard <peter@korsgaard.com>