14.04.4 RC images (20160217)

[Adam Conrad]

I've just kicked off a world image respin that should come out as
20160217 for everyone.  This includes a few security updates, two
last-minute stability updates, and the correct 14.04.4 versioning.

Given the testing on the last couple of images, I think it's fair
to say this is almost definitely the batch we'll be releasing on
Thursday, so please give them at least a boot/install/reboot smoke
test on all flavours and make sure all the images are functional.

Thanks in advance,

... Adam