[SRU cosmic] linux-buildinfo support

[Andy Whitcroft]

Add linux-buildinfo package support.  This package contains all of the
ABI information accumulated during the build.  This means we no longer
have to install that data onto the end-user system, and means we only
have to download the ABI data when doing getabis.

Pull request below.

Proposing for SRU to cosmic.

-apw

The following changes since commit 4961d6dd48e577eac572dad52e0179edc22a2736:

  UBUNTU: Ubuntu-4.18.0-11.12 (2018-10-23 18:59:44 +0200)

are available in the Git repository at:

  git://git.launchpad.net/~apw/ubuntu/+source/linux/+git/cosmic linux-buildinfo

for you to fetch changes up to fe7e277c1c27312f14481a85aea00cbeb6dfdb01:

  UBUNTU: [Packaging] buildinfo -- switch getabis configuration to new package (2018-12-03 12:20:32 +0000)

----------------------------------------------------------------
  * linux-buildinfo: pull out ABI information into its own package
    (LP: #1806380)
    - [Packaging] limit preparation to linux-libc-dev in headers
    - [Packaging] commonise debhelper invocation
    - [Packaging] ABI -- accumulate abi information at the end of the build
    - [Packaging] buildinfo -- add basic build information
    - [Packaging] buildinfo -- add firmware information to the flavour ABI
    - [Packaging] buildinfo -- add compiler information to the flavour ABI
    - [Packaging] buildinfo -- add buildinfo support to getabis
    - [Packaging] buildinfo -- switch getabis configuration to new package

  * linux packages should own /usr/lib/linux/triggers (LP: #1770256)
    - [Packaging] own /usr/lib/linux/triggers