pull: Drop some g_print(), replace others with async progress

We shouldn't g_print() from a library, particularly when the
expectation is that the client has an async progress set up.

This should fix the pull output extending the status line.
libostree: Remove g_print() from bootloader code

No need to be so chatty.
deploy: Less usage of g_print

No need to spam the console here.
admin: selinux-ensure-labeled: new builtin

Code like rpm-ostree generates disk images directly.  In order to
ensure SELinux labeling is correct, it currently has a helper program
that runs over the deployment root, then over the whole disk and to
only set a label if none exist.

In order to make it easier to write installers such as Anaconda
without having them depend on rpm-ostree (or whatever other
build-server side program), pull in the helper code here.
libostree: Add a better error if we fail to read keyring directory

I had accidentally put it in the -devel package and not noticed.
libostree: Add API to append a GPG signature

This will be used by rpm-ostree which needs to use an external program
to sign commits.
libostree: Fix crash if output is not a tty

This was a recent regression.
Remove custom SELinux policy

This was a temporary hack until the requisite bits landed upstream in
the Fedora SELinux policy.
TODO: update
Disable test-sysroot.test

It hangs on test-sysroot.js:40 during GLib.spawn_command_line_sync - it seems it can't
handle sh -c and the inner process becomes a zombie
Revert "Disable test-sysroot.test"

This reverts commit 73868a96d14fa13e69d9df778d2363b89f41fef5.
test-sysroot: Use GSystem to spawn subprocess

I was getting a weird hang in the installed tests with the shell as a
zombie process, not reaped by the parent, which was just stuck in
select() on the output pipes.  The thing is we don't actually want to
capture stdout/stderr, we just want to inherit.

GSystem.Subprocess makes that possible, so let's just use it now that
it's a proper installed library.
Add "ostree admin instutil", move selinux-ensure-labeled there

There are going to be a few utilities that are only useful for
installers and disk image creation tools.  Let's not expose them all
at the toplevel; instead, hide them under "instutil".
libostree: Add ostree_bootconfig_parser_clone()

This will be necessary to fix ostree_deployment_clone(), but is
potentially useful on its own for other consumers.
libostree: Fix ostree_deployment_clone() to also clone bootconfig

This way one can easily mutate it for a new deployment list.
libostree: Add ostree_sysroot_deployment_set_kargs()

It turns out people sometimes want to be able to change the kernel
arguments.  Add a convenient API to do so for the current deployment.

This will be used by Anaconda.
core: Add "admin instutil set-kargs"

This will be used by Anaconda as a convenience command to set the
bootloader arguments.
pull: End status line on error as well

This way we don't append the error to the current line.
pull: Don't print, just use progress callback

More work on removing g_print() from the library.
Release 2014.3