title: Emacs 25.1 on lubuntu 16.04 won't configure due to missing libpng
body: <p>I am attempting to install emacs 25.1 on lubuntu 16.04, and having some trouble. After downloading and extracting the tar, I navigate to the emacs 25.1 directory then..
      <code>./configure</code></p>
  
  <p>The configuration stops when I receive the message</p>
  
  <pre><code>configure: error: The following required libraries were not found:
      libpng
  Maybe some development libraries/packages are missing?
  If you don't want to link with them give
       --with-png=no
  as options to configure
  </code></pre>
  
  <p>When I try <code>sudo apt install libpng-dev</code></p>
  
  <p>I get the message</p>
  
  <p><code>Note, selecting 'libpng12-dev' instead of 'libpng-dev'
  libpng12-dev is already the newest version (1.2.54-1ubuntu1).
  0 upgraded, 0 newly installed, 0 to remove and 9 not upgraded.
  </code>
  I tried reinstalling libpng12-dev using the below string, which didn't help at all.</p>
  
  <pre><code>sudo apt-get install --reinstall libpng12-0=1.2.54-1ubuntu1
  </code></pre>
  
  <p>I'm stuck here, I've googled around for a while and can't find any solutions that have actually worked.</p>