Upgrade Ubuntu Desktop/Server from 16.04 (Xenial Xerus) to 16.10 (Yakkety Yak)

http://www.ubuntugeek.com/upgrade-ubuntu-desktopserver-from-16-04-xenial-xerus-to-16-10-yakkety-yak.html (Posted on October 24, 2016 by ruchi)

Open the "Software & Updates" Setting in System Settings.
Select the 3rd Tab called "Updates".

Set the "Notify me of a new Ubuntu version" dropdown menu to "For any new version".
Press Alt+F2 and type in "update-manager" (without the quotes) into the command box.
Update Manager should open up and tell you: New distribution release ‘16.10' is available.

If not you can also use "/usr/lib/ubuntu-release-upgrader/check-new-release-gtk"
Click Upgrade and follow the on-screen instructions.

Install the update-manager-core package if it is not already installed.
Make sure the Prompt line in /etc/update-manager/release-upgrades is set to normal.
Launch the upgrade tool with the command sudo do-release-upgrade.
Follow the on-screen instructions.

--

--> emacs
if you got emacs error with libpng12.so.0

 : emacs: error while loading shared libraries: libpng12.so.0: cannot open shared
 : object file: No such file or directory

- if error or not registered
sudo apt-get install libpng12-0
 : E: Package 'libpng12-0' has no installation candidate

- download and manually install
  https://launchpad.net/ubuntu/yakkety/amd64/libpng12-0/1.2.54-1ubuntu1

 amd64 build of libpng 1.2.54-1ubuntu1 in ubuntu xenial PROPOSED produced these files:
 libpng12-0_1.2.54-1ubuntu1_amd64.deb (113.7 KiB)

sudo dpkg -i libpng12-0_1.2.54-1ubuntu1_amd64.deb