Add disk space check.

gcimagebundle now checks disk free space.  If there is not enough free disk space,
it will abort before copying the files. Currently, the disk space calculation
overestimates the space required.  The user can use --skip_disk_space_check to
disable the disk space check.
Fixes authorized_keys file permissions

Owner and group id are not inherit when calling shutil move. This commit
moves setting permissions logic for the authorized_keys file to be sure
that the final destination file has the proper permissions.
Merge pull request #47 from jeremyje/master

Add pauses back to gcimagebundle.
Merge pull request #45 from yueluog/master

Add disk space check.
fixes #48, account manager was not starting on upstart systems
support both CentOS and Debian derivatives
Merge pull request #49 from erjohnso/master

fixes #48, account manager was not starting on upstart systems
Merge pull request #46 from frodenas/master

Fixes authorized_keys file permissions
Update block_disk.py

in case you specify gcimagebundle -d /dev/sda1
the message is not leading you to specify a disk, it makes you confused about why a single partition
is not a single partition
Fixes an issue that blocked the version displaying
Add UTC timestamp to gcimagebundle logging.
Merge pull request #56 from yueluog/master

Merge pull request #56: Add UTC timestamp to gcimagebundle logging.
Changing DesiredAccounts._GetAttribute method to catch 404 HTTPError and raise all errors
Changing DesiredAccounts class to surface errors to the caller and handling errors at the top level. This helps us put a sleep in the while loop in case of errors to help prevent log spam.
Fixing typo in error code which I was using to test the changes and didn't actually meant to commit.
Minor changes
fix(google-daemon): use * for the passwd not !

useradd defaults to using ! as the "locked" password marker.
Unfortunatly, openssh interprets this to mean that it shouldn't let the
user in via ssh if PAM is missing. Work around this by using the *
marker which also means locked but is allowed by openssh.
Merge pull request #57 from HimanshuVasishth/master

Improving error handling and logging
feat(accounts): add users to the sudo group by default

On CoreOS the sudo group gets passwordless sudo. Add users to this
group.
Merge pull request #60 from coreos/add-sudo-group

feat(accounts): add users to the sudo group by default
Merge pull request #55 from coreos/master

fix(google-daemon): use * for the passwd not !