busybox security and bug fix update

[1:1.2.0-13]

• Resolves: #768083 ‘busybox various flaws’ including:
  ‘buffer underflow in decompression’
  ‘udhcpc insufficient checking of DHCP options’
  [1:1.2.0-12]
• Resolves: #756723
  ‘Kdump fails after findfs subcommand of busybox fails’
  [1:1.2.0-11]
• Resolves: #689659
  ‘‘busybox cp’ does not return a correct exit code when ‘No space left on device’’