Replace the current Yubikey PBA implementation with the previous one.

Rationale:
  * The main reason for choosing to implement the PBA in accordance
    with the Yubico documentation was to prevent a MITM-USB-attack
    successfully recovering the new LUKS key.
  * However, a MITM-USB-attacker can read user id and password when
    they were entered for PBA, which allows him to recover the new
    challenge after the PBA is complete, with which he can challenge
    the Yubikey, decrypt the new AES blob and recover the LUKS key.
  * Additionally, since the Yubikey shared secret is stored in the
    same AES blob, after such an attack not only is the LUKS device
    compromised, the Yubikey is as well, since the shared secret
    has also been recovered by the attacker.
  * Furthermore, with this method an attacker could also bruteforce
    the AES blob, if he has access to the unencrypted device, which
    would again compromise the Yubikey, should he be successful.
  * Finally, with this method, once the LUKS key has been recovered
    once, the encryption is permanently broken, while with the previous
    system, the LUKS key itself it changed at every successful boot,
    so recovering it once will not necessarily result in a permanent
    breakage and will also not compromise the Yubikey itself (since
    its secret is never stored anywhere but on the Yubikey itself).

Summary:
The current implementation opens up up vulnerability to brute-forcing
the AES blob, while retaining the current MITM-USB attack, additionally
making the consequences of this attack permanent and extending it to
the Yubikey itself.
nss: update to 3.15.4
firefox: update to 27.0.
perf: Allow proceeding in build even if patch fails.
Patching fails for linux 3.13 but it builds OK.
perf: Make build fix for 3.13 cleaner.
gnash: Hack to define nullptr as NULL, since some included mozilla headers seem to want nullptr
Merge remote-tracking branch 'official/master' into firefox_27
mumble: Upgrade 1.2.4 -> 1.2.5
murmur: Upgrade 1.2.4 -> 1.2.5
spring: disable parallel building, as it breaks on Hydra

(cherry picked from commit e43018e0196dd6af57087ecb6aaa3af7b17776ab)
llvmPackages on darwin: attempt to fix build by using gcc48
andagii: fix fetch by providing a different user-agent

Close #1706.
Merge pull request #1702 from vlstill/perf-fix

perf: Allow proceeding in build even if patch fails.
kde410.kde_workspace: fix CVE-2013-4132 by upstream patch
linux: minor updates 3.12.10, 3.10.29, 3.4.79
Merge #1699: firefox-27.0 and nss-3.15.4
gnome3.gnome_control_center: build and fix runtime deps
osc: Add an OBS (open build system) CLI client.
Add fedpkg, koji &c. + their python dependencies.
rpm: Build python bindings (--enable-python).