title: What are ALL_BUILD and ZERO_CHECK and do I need them?
body: <p>I've created a simple CMakeLists.txt:</p>
  <pre><code>cmake_minimum_required(VERSION 2.8)
  project (HelloWorld)
  add_executable (HelloWorld main.cpp)
  </code></pre>
  <p>When I generate a VS2012 or VS2010 project from CMake, however, I get these 2 additional entries - ALL_BUILD and ZERO_CHECK.
  I don't understand their purpose, do I need them?</p>
  <p><a href="https://i.stack.imgur.com/jVFgk.png" rel="noreferrer"><img src="https://i.stack.imgur.com/jVFgk.png" alt="enter image description here" /></a></p>