Code review comment for lp:~mvo/apport/kernel-crashdump

Please review/merge support for kernel crashdump retracing.

Overview:
* bin/kernel_crashdump:
  - needs the add_os_info() to get uname and architecture to make the retracing easier (and is cheap to obtain)
* bin/apport-retrace:
  - small changes to make it friendlier for the kernel output
* apport/report.py
  - add_kernel_info: that is not yet split up, but I think the final splitting depends on what information the kernel team wants here, it should do no harm to merge it and append later
* backends/packaging-apt-dpkg.py
  - uses hardcoded ddebs.ubuntu.com currently which is ugly. but kernel-image-debug packages are not in the Packages.gz so this method seems to be required for now

Thanks and feedback welcome