linux-initrd: Produce cpio archives with zeroed timestamps, etc.

* guix/cpio.scm (file->cpio-header*): New procedure.
* gnu/build/linux-initrd.scm (write-cpio-archive): Add #:file->header argument
  to 'cpio:write-cpio-archive'.

linux-initrd: Populate cpio archives in a deterministic order.

* gnu/build/linux-initrd.scm (write-cpio-archive)[files]: Use 'sort' instead
  of 'reverse'.

linux-initrd: Use (guix cpio) instead of GNU cpio.

* gnu/build/linux-initrd.scm (write-cpio-archive): Remove 'open-pipe*' and
  related calls.  Compute list of files in 'files' variable.  Use
  'cpio:write-cpio-archive'.  Remove #:cpio parameter.
  (build-initrd): Remove #:cpio parameter.
* gnu/system/linux-initrd.scm (expression->initrd): Likewise, and adjust
  BUILDER accordingly.  Add (guix cpio) to #:modules.

Merge branch 'master' into core-updates

gnu: Make 'mount' interface in static Guile consistent with Guix API.

Rather than expecting a pointer, the version of 'mount' in
guile-static-stripped now takes a string for the 'options' argument, just like
the 'mount' procedure in (guix build syscalls).

* gnu/packages/patches/guile-linux-syscalls.patch (mount): Expect a string or
  #f for 'options' argument.
* gnu/build/file-systems.scm (mount-file-system): Use new 'mount' interface.

Merge branch 'master' into core-updates

install: Turn off deduplication for the binary tarball.

* gnu/build/install.scm (register-closure): Add #:deduplicate? parameter and
  honor it.
  (populate-single-profile-directory): Likewise.
* gnu/system/install.scm (self-contained-tarball): Pass #:deduplicate? #f.
  Invoke tar with --check-links.

Merge branch 'master' into core-updates

install: Really overwrite TARGET/var/guix/profiles/system-1-link.

* gnu/build/install.scm (populate-root-file-system): Delete system-1-link
  under TARGET, not under /.  Use 'catch' and check for EEXIST instead of
  (false-if-exception (delete-file ...)).

Merge branch 'master' into gtk-rebuild

gnu: linux-boot: Remove outdated and misleading comment.

* gnu/build/linux-boot.scm (boot-system): Remove outdated comment.

Merge branch 'master' into gtk-rebuild

Conflicts:
	gnu/packages/gtk.scm

system: activate-ptrace-attach: Handle kernels without YAMA support.

* gnu/build/activation.scm (activate-ptrace-attach): Check for the existence
  of /proc/sys/kernel/yama/ptrace_scope before trying to write to it.

activation: Make user copies of the skeletons writable.

* gnu/build/activation.scm (make-file-writable,
  make-skeletons-writable): New procedures.
  (copy-account-skeletons): Call 'make-file-writable' after 'copy-file'.
  (add-user): Add call to 'make-skeletons-writable'.

Merge branch 'master' into core-updates

install: Make /var/lock.

Reported by 宋文武 <iyzsong@gmail.com>.

* gnu/build/install.scm (directives): Add /var/lock.

file-systems: Use a second 'mount' call for read-only bind mounts.

* gnu/build/file-systems.scm (MS_REMOUNT): New constant.
  (mount-file-system): Add 'flags' local variable.   When FLAGS has
  MS_BIND & MS_RDONLY, call 'mount' with MS_REMOUNT.
* gnu/services/base.scm (file-system-service) <start>: Likewise.

Merge branch 'master' into core-updates

Conflicts:
	gnu-system.am
	gnu/packages/gstreamer.scm

install: Add a procedure to build a self-contained binary tarball.

Suggested by Pjotr Prins <pjotr.public12@thebird.nl>
at <http://lists.gnu.org/archive/html/guix-devel/2015-04/msg00229.html>.

* gnu/build/install.scm (populate-single-profile-directory): New procedure.
* gnu/system/install.scm (self-contained-tarball): New procedure.
* Makefile.am (guix-binary.%.tar.xz): New target.

Merge branch 'master' into core-updates