title: Different Condition checks supported in binding.gyp
body: <p>I am very new to nodejs addons. I would like to know what are the different conditions that can be checked in binding.gyp. I am aware of checking the os platform using</p>
  
  <pre><code>'conditions': [
            ['OS=="linux"', {}
            ]
  </code></pre>
  
  <p>What are the other variables available similar to OS? Is it possible to know the version of nodejs in the similar way?</p>
  
  <p>Thanks in advance</p>