thunderbird security update

[1.5.0.12-16.0.1.el4]

• Add thunderbird-oracle-default-prefs.js for errata rebuild and remove
  thunderbird-redhat-default-prefs.js
  [1.5.0.12-16]
• Update patchset to fix regression as per 1.8.1.17
  [1.5.0.12-15]
• Rebuild with system nss and nspr
  [1.5.0.12-14]
• Add patches for backported fixes from 1.8.1.16
  [1.5.0.12-13]
• Respun for mozilla bugs #439035,#439735,#440308
  [1.5.0.12-12]
• Update patchset to fix regression as per 1.8.1.15