LP#1516686 -- clean up source generation and improve testing performance

[Andy Whitcroft]

We have slowly been cleaning up the kernel source package generation to
reduce the cruft therein with the aim of reducing the noise in kernel
deltas to make review simpler and easier for the Archive Admins; things
such as ensuring consistant ordering for control information and removing
temporary files we do not use in the source package.  We have in parallel
been improving the ADT test rebuild to save testing time, not rebuilding
at all when only testing for the kernel we just built.

Following this email are patch kits for precise, trusty,
trusty/lts-backport-utopic, and vivid to harmonise all of these with
the current state of the art.  The kits in the main represent clean
cherry-picks back to those releases from wily.  The one exception is
the patch below for trusty which was collapsed into a cloud-tools patch
incorrectly:

  [trusty/master-next 3/4] UBUNTU: [Tests] rebuild -- fix up rebuild test

These should only have build/test time effects, not code effects are
present.

Proposing for SRU to precise, trusty, trusty/lts-backport-utopic, and
vivid.

-apw