Various manpage / usage blurb improvements

Corrections, clarifications, consistency.

Not a comprehensive overhaul of the manpages; they do still need work.
These are just flaws I've noted while studying the ostree command syntax.

https://bugzilla.gnome.org/show_bug.cgi?id=740097
Refactor command-line parsing

Refactor command-line parsing to better utilize GOptionContext.  This
eliminates most of the manual parsing and global options are now shown
in the help output.

Here's a sample:

    $ ostree admin --help
    Usage:
      ostree admin [OPTION...] --print-current-dir|COMMAND

    Builtin "admin" Commands:
      cleanup
      config-diff
      deploy
      init-fs
      instutil
      os-init
      status
      switch
      undeploy
      upgrade

    Help Options:
      -h, --help         Show help options

    Application Options:
      --sysroot=PATH     Create a new OSTree sysroot at PATH
      -v, --verbose      Print debug information during command processing
      --version          Print version information and exit

https://bugzilla.gnome.org/show_bug.cgi?id=740295
grub2: If using --sysroot, run in chroot

In Anaconda, we're using "ostree admin --sysroot=/mnt/sysimage
instutil set-kargs", and it was working before, but newer versions of
lorax strip out /etc/system-release which grub2 wants.

That was wrong anyways as we want the /etc/system-release from the
target root.

(Man, grub2 sucks...give me a declarative config file format I can just
 write)

https://bugzilla.gnome.org/show_bug.cgi?id=740697
trivial: Fix typo in previous commit
tests: Fix u-boot test failure

This bit needs to be specific to syslinux.
Release 2014.12
docs: Fix a pile of Docbook validation errors

At least now validates with RNG mode in Emacs.
README.md: Mention patches and test suite
docs: Add verbose option to manual
Revert "ostree-repo-pull: Remove currently #if 0 static delta code"

This reverts commit 1c2e20af25b21abc0dee1547a0d5bad1a21c0b58.
Static deltas support

https://bugzilla.gnome.org/show_bug.cgi?id=721799
test-rollsum: Process all input, print more statistics

Copying the bup code, we need to loop over all chunks even after
hitting the rollsum returning 0.

Also print more statistics.
fix --help for static-delta

Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com>
test: Fix invocation of static-delta

Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com>