Merge pull request #3254 from shykes/onbuild

New build instruction: ONBUILD defines a trigger to execute when extending an image with a new build
docs: Installation on Mac OS X 10.6 Snow Leopard
Docker-DCO-1.1-Signed-off-by: O.S. Tezer <ostezer@gmail.com> (github: ostezer)
Update RELEASE-CHECKLIST to mention how to get a decent contributors list

Docker-DCO-1.1-Signed-off-by: Andrew Page <admwiggin@gmail.com> (github: tianon)
Merge pull request #3918 from ostezer/master

docs: Requirements And Installation on Mac OS X 10.6 Snow Leopard
Update .mailmap and AUTHORS

Docker-DCO-1.1-Signed-off-by: Andrew Page <admwiggin@gmail.com> (github: tianon)
Merge pull request #3926 from tianon/update-mailmap

Update .mailmap and AUTHORS
Fixes headings in Table of Contents, link from FAQ.
Docker-DCO-1.1-Signed-off-by: Andy Rothfusz <github@developersupport.net> (github: metalivedev)
mac-installation-docs: Update the installation dir.
Docker-DCO-1.1-Signed-off-by: O.S. Tezer <ostezer@gmail.com> (github: ostezer)
Merge pull request #3927 from tianon/release-checklist-mention-contributors

Update RELEASE-CHECKLIST to mention how to get a decent contributors list
Merge pull request #3929 from ostezer/master

mac-installation-docs: Update the installation dir.
Merge pull request #3928 from metalivedev/fixheadings

Fixes headings in Table of Contents, link from FAQ.
Bump to version 0.8.0
Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@crosbymichael.com> (github: crosbymichael)
remove mention of #docker-meeting

Docker-DCO-1.1-Signed-off-by: Sven Dowideit <SvenDowideit@home.org.au> (github: SvenDowideit)
docs/installation/google: remove -mtu flag
Merge pull request #3933 from proppy/patch-1

docs/installation/google: remove -mtu flag
be a little more explicit about what WORKDIR does

Docker-DCO-1.1-Signed-off-by: Sven Dowideit <SvenDowideit@home.org.au> (github: SvenDowideit)
Merge pull request #3916 from crosbymichael/bump_v0.8.0

Bump to v0.8.0
Merge branch 'release' into merge_release_v0.8.0

Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@crosbymichael.com> (github: crosbymichael)
Change version to v0.8.0-dev
Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@crosbymichael.com> (github: crosbymichael)
Merge pull request #3941 from crosbymichael/merge_release_v0.8.0

Merge release v0.8.0