Log Message:
libVNCServer: update to 0.9.12

Overall changes:
  CMake now is the default build system, Autotools were removed.
  In addition to TravisCI, all commits are now build-tested by AppVeyorCI.

LibVNCServer/LibVNCClient:
  Numerous build fixes for Visual Studio compilers to the extent that
  one can now build the project with these. The needed changes for
  successfully running stuff will be implemented in 0.9.13.
  Fixed building for Android and added build instructions.
  Removed the unused PolarSSL wrapper.
  Updated the bundled noVNC to latest release 1.0.0.
  Allowed to use global LZO library instead of miniLZO.

LibVNCClient:
  Support for OpenSSL 1.1.x.
  Support for overriding the default rectangle decode handlers (with
  hardware-accelerated ones for instance) thanks to Balazs Ludmany.
  vnc2mpg updated.
  Added support for X509 server certificate verification as part of the
  handshake process thanks to Simon Waterman.
  Added a TRLE decoder thanks to Wiki Wang.
  Included Tight decoding optimizations from TurboVNC thanks to DRC.
  Ported the SDL viewer from SDL 1.2 to SDL 2.0.
  Numerous security fixes.
  Added support for custom auth handlers in order to support additional
  security types.

LibVNCServer:
  Websockets rework to remove obsolete code thanks to Andreas Weigel.
  Ensured compatibility with gtk-vnc 0.7.0+ thanks to Micha  K pie .
  The built-in webserver now sends correct MIME type for Javascript.
  Numerous memory management issues fixed.
  Made the TightVNC-style file transfer more stable.