New 15.04 stable release

[Michael Vogt]

Hi all,

we are excited to announce a new Snappy Ubuntu Core stable release
(image 7 at 15.04/stable)!

Highlights of this release include:
- fix uefi boot
- support for secure boot
- version sort speedup
- add "current" symlink for the data dirs
- hw-assign fixes

The stable images were also updated
(http://releases.ubuntu.com/15.04/) to reflect the latest image
available in the stable channel (you can also find them
at http://cdimage.ubuntu.com/ubuntu-snappy/15.04/stable/20151013/)

If you find any issue please make sure to
usehttps://bugs.launchpad.net/snappy/+filebug to report them,
including the device and image revision you're currently using.


Happy snapping,

 - Michael and the snappy team