fix(router): gzip content types syntax fixed

gzip content types are only whitespace separated
fixed missing table on http://docs.deis.io/en/latest/managing_deis/router_settings/
docs(deisctl): add unit search paths behavior to README
fix(CHANGELOG): use SSL for github and recreate change entries
fix(readme): use relative link to deisctl in repo
Merge pull request #1939 from johanneswuerbach/patch-5

fix(router): gzip content types syntax fixed
Merge pull request #1946 from gabrtv/fix-deisctl-link

fix(readme): use relative link to deisctl in repo
Merge pull request #1943 from mboersma/redo-changelog

fix(CHANGELOG): use SSL for github URLs, recreate change entries
Merge pull request #1941 from mboersma/deisctl99-doc-search-paths

docs(deisctl): add unit search paths behavior to README
fix(deisctl): install only deisctl

./... means "this and all subpackages", but we only want to build
`deisctl`. The other problem seems to be that ./... doesn't actually
drop the main binary in the root.
Merge pull request #1950 from bacongobbler/build-deisctl

fix(deisctl): install only deisctl
refactor(makefile): cleanup and add release, dev-release target
refactor(tests): cleanup tests, move common logic into test-setup.sh
chore(tests): add log_phase helper

chore(tests): use log_phase in test-setup

fix(tests): log when testing docs

fix(tests): switch test-smoke to log_phase
fix(tests): install required go dependencies
fix(makefile): replace user-data inline
fix(tests): add DEISCTL_UNITS to test-setup
fix(docs): clean up sources and treat warnings as errors

Many deficiencies in the docs were being skipped over because
`sphinx-build` is lenient. Adding the `-W` flag treats issues
such as "missing reference" and "class not found" as errors.
fix(tests): add correct key to ssh-agent
fix(deisctl): create unit download URL properly after move to subdir
fix(makefile): use portable sed for make discovery-url