pitivi is marked for autoremoval from testing

[Debian testing autoremoval watch]

pitivi 0.97.1-1 is marked for autoremoval from testing on 2016-09-14

It (build-)depends on packages with these RC bugs:
818380: clang-3.7: __builtin_return_address() segfaults on s390x
828931: llvm-toolchain-3.7: FTBFS on i386 with gcc-6 and glibc 2.23