* build: bump PPAs to Go 1.13 (via longsleep), keep Trusty on 1.11
* travis, build, vendor: use own Go bundle for PPA builds
* travis, build, internal, vendor: smarter Go bundler, own untar
* build: updated ci-notes with new Go bundling, only make, don't test
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.