[release/1.4.15] build: improve debian packaging

This commit tweaks the debian packaging tool:

* All build environment metadata can now be overriden on the command
  line. This allows testing the CI build behaviour locally.
* -unstable packages now actually contain the binaries (oops)
* packages use Go 1.7 to build
* archiving is skipped for PR builds

(cherry picked from commit 4f7627972e)

build/ci-notes.md

@@ -1,5 +1,4 @@
-Debian Packaging
-----------------
+# Debian Packaging
 
 Tagged releases and develop branch commits are available as installable Debian packages
 for Ubuntu. Packages are built for the all Ubuntu versions which are supported by
@@ -8,6 +7,7 @@ Canonical:
 - Trusty Tahr (14.04 LTS)
 - Wily Werewolf (15.10)
 - Xenial Xerus (16.04 LTS)
+- Yakkety Yak (16.10)
 
 Packages of develop branch commits have suffix -unstable and cannot be installed alongside
 the stable version. Switching between release streams requires user intervention.
@@ -21,6 +21,29 @@ variable which Travis CI makes available to certain builds.
 We want to build go-ethereum with the most recent version of Go, irrespective of the Go
 version that is available in the main Ubuntu repository. In order to make this possible,
 our PPA depends on the ~gophers/ubuntu/archive PPA. Our source package build-depends on
-golang-1.6, which is co-installable alongside the regular golang package. PPA dependencies
+golang-1.7, which is co-installable alongside the regular golang package. PPA dependencies
 can be edited at https://launchpad.net/%7Elp-fjl/+archive/ubuntu/geth-ci-testing/+edit-dependencies
 
+## Building Packages Locally (for testing)
+
+You need to run Ubuntu to do test packaging.
+
+Add the gophers PPA and install Go 1.7 and Debian packaging tools:
+
+    $ sudo apt-add-repository ppa:gophers/ubuntu/archive
+    $ sudo apt-get update
+    $ sudo apt-get install build-essential golang-1.7 devscripts debhelper
+
+Create the source packages:
+
+    $ go run build/ci.go debsrc -workdir dist
+
+Then go into the source package directory for your running distribution and build the package:
+
+    $ cd dist/ethereum-unstable-1.5.0+xenial
+    $ dpkg-buildpackage
+
+Built packages are placed in the dist/ directory.
+
+    $ cd ..
+    $ dpkg-deb -c geth-unstable_1.5.0+xenial_amd64.deb