GNU IceCat 45 beta now available in Guix

[Mark H Weaver]

Hello Guix,

I'm pleased to announce the availability of GNU IceCat 45.3.0-gnu1-beta
with selected fixes cherry-picked from upstream, including all security
fixes introduced in Firefox ESR 45.4.0, specifically:

  CVE-2016-5250 - Resource Timing API is storing resources sent by
                  the previous page
  CVE-2016-5257 - Memory safety bugs fixed in Firefox 49 and Firefox ESR 45.4
  CVE-2016-5261 - Integer overflow and memory corruption in WebSocketChannel
  CVE-2016-5270 - Heap-buffer-overflow in
                  nsCaseTransformTextRunFactory::TransformString
  CVE-2016-5272 - Bad cast in nsImageGeometryMixin
  CVE-2016-5274 - use-after-free in nsFrameManager::CaptureFrameState
  CVE-2016-5276 - Heap-use-after-free in
                  mozilla::a11y::DocAccessible::ProcessInvalidationList
  CVE-2016-5277 - Heap-use-after-free in nsRefreshDriver::Tick
  CVE-2016-5278 - Heap-buffer-overflow in nsBMPEncoder::AddImageFrame
  CVE-2016-5280 - Use-after-free in
                  mozilla::nsTextNodeDirectionalityMap::RemoveElementFromMap
  CVE-2016-5281 - use-after-free in DOMSVGLength
  CVE-2016-5284 - Add-on update site certificate pin expiration

       Mark