* Targets linux only, to start.

7z does not currently extract file permissions from the dmg files
so we also extract the old mar file to copy the permissions.

The subkey that signed PyCrypto back in the days expired. We fall back
to the SHA256 check (which we already did in addition to the signature
check).

We ecountered on some machines failures to reproduce OS X builds.
The investigation seems to indicate that our old toolchain plays a
crucial role in this.

This patch replaces this old toolchain with a more modern clang/cctools
for building the tor part of the bundle. Resorting to `faketime` again
was necessary to cope with inserted timestamps.

This reverts commit 0348263efd1cb8a9eca8737f3dc7734ef75e0966.

Firefox is not ready for GCC 6 yet. See #20381 for further details.

When updating the OSX incremental MAR files after running dmg2mar, we check
that both the old and the new mar files contain code signing.

We don't check this while creating the incremental MAR files during the
build.

Bumping GCC to 6.2.0 is fixing our EMET incompatibilities. The exact
change on GCC's side causing this remains unclear, though.

We need to backout GCC changes that are causing a mingw-w64 build to
fail. For details see the bug report in GCC's bugtracker:

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77459

LeifEricson (blocked): Port 50000 --> 50001
Greenbelt (unblocked): Port 5881 --> 7013
Mosaddegh (blocked): Port 2934 --> 9332
MaBishomarim (blocked): Port 2413 --> 7920
JonbesheSabz (blocked): Port 1894 --> 4148
Azadi (unblocked): Port 4319 --> 6041