Added trousers, tpm-tools, and tboot.

Added lcp_writepol -Z option.
Added tpm-quote-tools for remote attestation.
Don't let rngd read /dev/tpm0.

Only one process can interact with the TPM module and
that process should be tcsd.  The tpm_rng kernel module
should instead be loaded and /dev/hwrnd be used to
read the TPM random generator.
Also, log which random generator devices are used by
rngd on startup.
Added TCSD (Trusted Computing Group Software Stack (TSS) daemon).

Start tcsd after systemd-udev-settle and run it in foreground.
Add types to tcsd config options.
Only disable TPM access by rngd when tcsd is enabled.
Added meta information and maintainer for trusted computing pkgs.
Changed trousers license from cpl to cpl10.
More helpful message when refusing to evaluate "broken" package

A "broken" package is one where either "meta.broken = true" or build
platform != meta.platforms.
Factor out allowUnfree,allowBroken help message

DRY.
perl: Disable tests

They're on the critical path for stdenv rebuilds.
bash: Update to 4.2-p47
util-linux: Update to 2.24.2
boost: Drop unnecessary runtime dependency on Python

The only file that actually referred to the Python interpreter was
share/boost-build/example/customization/inline_file.py. So get rid of
the whole example directory.
Remove the unmaintained (and AFAIK unused) stdenv for mingw
Another attempt to eradicate ensureDir

See c556a6ea46e71e1907d78b71fab36df30297b3ad.
Add a deprecation warning to ensureDir
gcc: Fix purity

Somewhere the no-sys-dirs.patch got disabled, so gcc was looking in
/usr/local/include and /usr/lib. Since I can't fix the patch easily,
I've borrowed the --sysroot trick from clang-wrapper. This causes
builtin paths to be prefixed with /var/empty
(e.g. /var/empty/usr/lib), which don't exist.
gcc: Slight builder cleanup
Darwin: Use xcrun to get the path to the SDK

Recent versions of Xcode don't install headers in /usr/include but
in a directory like

  /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.9.sdk/usr/include

So use that instead, falling back to /usr/include in case of an older
version of Xcode.