Update hack/make.sh with slightly clearer output and a more precise "are we in the Docker container?" check

Docker-DCO-1.1-Signed-off-by: Andrew Page <admwiggin@gmail.com> (github: tianon)
Fix 2720 -- Expanded documentation for docker run.
Docker-DCO-1.1-Signed-off-by: Andy Rothfusz <github@developersupport.net> (github: metalivedev)
Address feedback from @jamtur01.
Docker-DCO-1.1-Signed-off-by: Andy Rothfusz <github@developersupport.net> (github: metalivedev)
Make get.docker.io install directions slightly better by telling user exactly how to add themselves to the "docker" group

As a bonus, if the user has run this script the way we recommend (ie, without "sudo" or "su", run as their user), we can actually give them the exact command they'll need with their correct username substituted appropriately.

Docker-DCO-1.1-Signed-off-by: Andrew Page <admwiggin@gmail.com> (github: tianon)
add tests

Docker-DCO-1.1-Signed-off-by: Victor Vieux <victor.vieux@docker.com> (github: vieux)
fix convertion issues

Docker-DCO-1.1-Signed-off-by: Victor Vieux <victor.vieux@docker.com> (github: vieux)
 Add troubleshooting for missing cgroups on mint 16 #3602

Docker-DCO-1.1-Signed-off-by: Sven Dowideit <SvenDowideit@fosiki.com> (github: SvenDowideit)
network: insert masq rule

This fixes IP masquerading on systems with reject rules at the end of
the POSTROUTING table, by inserting the rule at the beginning of the
table instead of adding it at the end.

Docker-DCO-1.1-Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> (github: jpoimboe)
Make unclejack the official Vagrantfile maintainer

Docker-DCO-1.1-Signed-off-by: Andrew Page <admwiggin@gmail.com> (github: tianon)
Merge pull request #3846 from tianon/unclejack-maintainer

Make unclejack the official Vagrantfile maintainer
Merge pull request #3836 from SvenDowideit/mint-cgroups-lite-docs

 Add troubleshooting for missing cgroups on mint 16
Merge pull request #3842 from jpoimboe/iptables-insert-masq

network: insert masq rule
 Fix fun Travis DCO check YAML parsing issues (especially with commit messages that start with any kind of whitespace, like this one intentionally does)

Docker-DCO-1.1-Signed-off-by: Andrew Page <admwiggin@gmail.com> (github: tianon)
refactor all *FromJob functions

Docker-DCO-1.1-Signed-off-by: Victor Vieux <victor.vieux@docker.com> (github: vieux)
Merge pull request #3833 from vieux/fix_env_conversion_issues

Fix env conversion issues in env
remove TestAllocateTCPPortLocalhost faillure in tests

Docker-DCO-1.1-Signed-off-by: Victor Vieux <victor.vieux@docker.com> (github: vieux)
Merge pull request #3854 from vieux/fix_tests

remove TestAllocateTCPPortLocalhost faillure in tests
fix TestExitCode

Docker-DCO-1.1-Signed-off-by: Victor Vieux <victor.vieux@docker.com> (github: vieux)
- Fixed the last cli.call's parameter from CmdSearch

Docker-DCO-1.1-Signed-off-by: Roberto Hashioka <roberto.hashioka@docker.com> (github: rogaha)
Merge pull request #3859 from rogaha/add_missing_attributes

- Fixed the last cli.call's parameter from CmdSearch