make additional tests optional

- Remove them from the MANIFEST as they are
  not supposed to be distributed.
Merge pull request #654 from MartinNowak/optionalTests

[2.065] make additional tests optional
core.sys.posix.fcntl: Fix F_GETLK/F_SETLK/F_SETLKW on Linux/X86_64
Merge pull request #699 from CyberShadow/fcntl64

core.sys.posix.fcntl: Fix F_GETLK/F_SETLK/F_SETLKW on Linux/X86_64