Don't autostart iceweasel...

...but notify when Tor is ready
Uncomment tor bootstrap progress function
Warn before launching iceweasel if Tor isn't ready
Update iceweasel profile generation script
Language fixes

- Avoid using contractions
- Say "browse the Internet"
- Use "start" instead of "launch"
Make test suite use native ruby + rjb instead of JRuby etc.
Switch from systemtimer to Ruby's timeout module in test suite.

systemtimer was relevant in Ruby < 1.9 (and is only available in for
such versions of Ruby in Debian).
Take screenshots through Sikuli instead.

This is much more reliable, and has fewer dependencies.
Update test suite setup docs.
Drop some unnecessary dependency checks.
Merge branch 'devel' into test/rjb-migration
Wheezy's cucumber is good enough for the test suite.
Fix fuzzy string.
[de] small translation
Merge branch 'devel' into test/rjb-migration

Conflicts:
	features/step_definitions/common_steps.rb
	features/step_definitions/usb.rb
Merge remote branch 'origin/bugfix/fix-tag-existence-detection' into stable
Merge remote-tracking branch 'origin/master' into feature/incremental-upgrades
Revert "Revert "Run tails-update-frontend at session login time, after waiting for Tor to work.""

This reverts commit 5d039b3a4314e470e93a998b336b49e08ed9bb82.

That is, once the user is logged-in and Tor is working, run
tails-upgrade-frontend. This still partly duplicates the security check, stay
tuned for better integration.
Rename and adapt tails-update-frontend.desktop to match current terminology and script name.
tails-security-check: make warnings fatal.