Install ca-certificates. Fixes #111
Adding flags for supporting backports kernel
Adding a preference of backports kernel when requested
Updating backport sources when backport is requested
GCE deb rename: image_bundle->python-gcimagebundle
Add script changing NTP server address.
Fixes after Jimmy Kaplowitz review:

 * use sed with -i option instead of grep to avoid creation of temp file
 * add comment to ntp.conf file explaining configuration change
 * change comments explaining that NTP server is located on host machine
Remove existing lines with server addresses instead of commenting them.
Do not force sed to create backup copy.
Merge pull request #1 from HimanshuVasishth/master

Add support for creating images with backports kernel
Merge pull request #2 from rybaktomasz/google-master

Add script changing NTP server address
Initially set the hostname to localhost to workaround startup error.
Better comment for setting default hostname.
Merge pull request #3 from jeremyje/patch-1

Workaround for the hostname not initially being set on boot.
Add note about bootstrap-vz
Merge pull request #135 from google/master

GCE shell branch work, November 2013 through now
Merge remote-tracking branch 'upstream/master'