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)
TravisCI and AppVeyor run the tests in very slow VMs.
Some of our tests can't cope with that. Running less tests
in parallel should make them somewhat less flakey.
(cherry picked from commit b0a6b979a3)
The new build script, ci.go, replaces some of the older shell scripts.
ci.go can compile go-ethereum, run the tests, create release archives
and debian source packages.
(cherry picked from commit 6c33ba14a4)
