New snappy 15.04 stable release

[Alexander Sack]

Hi all,

we are excited to announce a new Snappy Ubuntu Core stable release
(image 5 at 15.04/stable)!

Highlights of this release include:
 - a clean REST API that exposes snappy admin operations in a
convenient manner for local software.
 - ubuntu-core has been augmented through addition of ppp and watchdog
middleware
 - ubuntu-core has new configuration options for ubuntu-core:
    - basic network management is now possible using familiar ifupdown syntax
    - kernel modules can be blacklisted and options tweaked using
modprobe.d syntax
    - modem/ppp configs can be set enabling WWAN use cases
    - watchdog can be configured through snappy config ubuntu-core
 - "snappy services" command adds convenience on how to handle services
    - easy start/stop/status and log of snappy services
 - We moved to static grub.cfg avoiding the need to update-grub on upgrade
 - Writable partition auto resize on first boot to max disk space
 - 512-byte image alignment for easier flashing to block devices
 - internationalization of all strings in snappy tool
 - support for systemd service type: forking
 - gpio access via hw-assign is now working
 - store-id config and ubuntu-device-flash option are now in place and working

Please note that the initial boot after upgrade may take some time
when its syncing the updated kernels on grub based systems. This is a
one-time process and will only happen on this upgrade.

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/20150917/)

We also updated ubuntu-device-flash in the Snappy Tools PPA
(https://launchpad.net/~snappy-dev/+archive/ubuntu/tools). Please use
this PPA if you want to create an image with ubuntu-device-flash.

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

For more details about the bugs fixed for this milestone, please check
https://launchpad.net/snappy/+milestone/15.04.3

An image for the RaspberryPi2 with all the above features can be
expected within the next days. We will switch to a 4.2 kernel and this
round will be the last separately produced RPi2 image. Future releases
will happen alongside the normal image publication process as a
supported snappy architecture.

Happy snapping,

 - Alexander and the snappy team