(maint) tidy build steps, fix permissions and add uninstall recipe#9

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johnmccabe wants to merge 6 commits intoavsm:masterfrom

johnmccabe:maint/master/tidy_build_steps_and_fix_permissions

Commits on Jan 31, 2017

tidy image build steps
John McCabe
committed
Ensures ssh uses no connection sharing (`-S none`)

netj
authored and
John McCabe
committed
Fixes tini path

netj
authored and
John McCabe
committed
Set ownership of authorized_hosts to root
John McCabe
committed
add uninstall recipe to makefile
John McCabe
committed
make docker-entrypoint.sh executable
John McCabe
committed