We don't have to any more (after the TBB migration) since we
explicitly set up the ones we want to use. This should speed up the
start and reduce the memory footprint.

And use it consistently in all places instead of using the value as a
magic constant.

Extracting and then compressing the whole langpack/omni.ja isn't
necessary and takes a lot of time. Tests show a 50% reduction in
startup time.

After installing incremental upgrades Tails' root filesystem consists
of a stack squashfs:s, not only filesystem.squashfs. When not stacking
them correct we may end up using the Tor Browser (Firefox) from an
older version of Tails, or with no Tor Browser at all, as in the
upgrade from Tails 1.1.2 to 1.2, when we migrated from Iceweasel to
the Tor Browser.

Based on patch contributed by sanic.

It was added by mistake when adapting the script for the
TBB-migration.

It was a relic of the TBB 3.x times when the profile was located in
the parent directory of the TBB browser files.

Also patch Tails Greeter with the updated path. That patch should
be dropped once it's been upstreamed into Tails Greeter.

That way one only has to remember to always call firefox with
exec_firefox(), and not to set LD_LIBRARY_PATH. As an example, this
was forgotten for Tor Launcher, which also was fixed.

The libstdc++6.so we have (from Debian Wheezy) is too old.

This will prevent the browser from hanging for several minutes will
trying to contact CUPS if a user accidentally presses CTRL+P or tries
to go to File -> Print.

Adapted from patch sent by Kill Your TV.

TBB_EXT was a typo.

The Unsafe Browser camoufalge was broken since the browser profile was
owned by root, no the user running the tails-activate-win8-theme
script, which require that it is writable for that user.

It turns out that the branding's name of the browser can differ quite
a bit between different langpacks, e.g. in Arabic it's written in
Arabic, but in languages using latin based it's often "(Mozilla)?
Firefox". Hence we must set the value according to the key, which is
the saner way, instead of simply replacing values.

Instead of installing the iceweasel package (and friends) we now fetch
the TBB tarballs at build-time and extract the Tor Browser, browser
add-ons and langpacks, and browser user data into sensible places. We
try to keep something like the old organization as much as possible.

Unfortunately this drops language support to whatever subset that the
TBB supports.

Commit dadb276ff drops this operation, and instead only removes the bookmarks
from the already created profile in /home/clearnet. This is incorrect (and
apparently untested): when no bookmarks exist on Firefox startup, it imports
the default ones from the system-wide profile skeleton.

So, here we remove bookmarks from both places.

The Search Bar is removed in the Windows 8 camouflage, so having
Wikipedia as the default cannot be used as a stealthy visual indicator
any more. We already have "Unsafe Browser" in both the window title,
and the button to the right of the URL box, which should make it clear
enough which browser is used.

If we're in camouflage mode we want it to be applied to the Unsafe
Browser as well. However, the camouflage activation script modifies
the *user's* own profile, not the system one, so it must be present at
this point, and then it's easier to also make all the other changes to
the user's profile since any changes to the system profile will not be
copied back in.

Running `notify-send` as root doesn't show anything, so we fallback on
our reliable `tilas-notify-user` instead.

It does not need Tor to be ready.

This function is not used anywhere, and obviously was not even tested, given the
typo (${dialob_text}) it contains.

GSettings can't be set with sudo from GDM's PostLogin on Wheezy (tried both with
"gsettings set" and "dconf write"), so we'll have to do this otherwise.

Then:

* Adapt the Unsafe Browser script accordingly: make it run
  tails-activate-winxp-theme as the clearnet user. This likely won't work
  either, for the same reason as why we're doing this entire commit at all,
  so likely this one will need more adaptation. We'll see.

* Don't try to delete /etc/skel/Desktop/*.desktop: it seems entirely useless
  (the users we need have already been created) and can't work now that we don't
  run this script as root anymore.

Else, the Unsafe Browser complains that "Iceweasel is configured to use a proxy
server that can't be found." and cannot connect to the Internet.