title: How to change Visual Studio 2017 default language version for all projects?
body: <p>How to set language version on C#7.0 for all projects?</p>
  
  <p><img src="https://i.stack.imgur.com/DWCJg.png" alt="Project/Properties/Build/Advanced.../Advanced Build Settings screen"></p>
  
  <p>Where does default parameter come from, I want to change default value</p>
  
  <p>PS: I do not mean the UI language</p>