Add Developer Certificate of Origin Text

We purposely chose to license Docker under the Apache 2.0 license. This is a well-known
license, which is popular for its permissive and flexible properties, while still
encouraging a collaborative community. It also makes certain representations with regard
to contributions, and the rights given to contributors, the project, people who use Docker,
people who modify Docker, etc.

This approach to contributions is inspired by the popular Linux Developer
"Certificate of Origin". This approach makes it simple for new contributors to get started,
and avoids bureaucracy in tracking contributions and contributors.

To indicate accordance, each individual contribution to the Project is signed off by the
developer, using his or her real name, email address, and github handle in the format below:

	Docker-DCO-1.0-Signed-off-by: Joe Smith <joe.smith@email.com>
Merged with master
Return meaningful error for meaningless Dockerfiles
add REMOTE_TODO
Make blank -H option default to the same as no -H was sent
Fix "docker load" help by removing "SOURCE" prompt and mentioning STDIN

Fixes #3383
Add more TestBuild Dockerfiles, especially for making sure manual RUN echo '#!...' continues to work correctly
Cleanup: runtime.getFullName is deprecated by getFullName
Upgrade VBox Guest Additions (Fix #3425)
Check standalone header when pinging a registry server. Standalone has to be true to use basic auth (in addition to previous requirements)
Extract cgroups utilities to own submodule.

Use mountinfo rather than for cgroups parsing.
Make helper method private and change name.
Makes method naming more explicit rather than GetThisCgroup.
Use upstream term subsystem rather than cgroupType.
Fix #3149: port mapping of TCP + UDP

Signed-off-by: Tzu-Jung Lee <roylee17@gmail.com>
Bump version to v0.7.3
Just pass the container in RegisterLinks(), no need to lookup by name again
Merge pull request #3439 from dotcloud/bump_v0.7.3

Bump v0.7.3
Change version to 0.7.3-dev
Changelog date typo fix: 2013-01-02 -> 2014-01-02
Merge pull request #3448 from tmahesh/patch-1

Changelog date typo fix: 2013-01-02 -> 2014-01-02
Spelling error.
Merge pull request #3454 from sudosurootdev/master

Fix spelling error in hack/make.sh comment