title: LuaL_openlibs() and sandboxing scripts
body: <p>I am embedding Lua (5.1) in a C/C++ application.</p>
  
  <p>I am using the <code>LuaL_openlibs()</code> function to load the base libs. However, this function loads some other libraries which I want to disable so that they are not available to my Lua scripts.</p>
  
  <p>Specifically, I want to disable the IO and OS modules. Is there a function I can call to programmativally disable (or unload) these modules so that I can create a safe sandbox environment for running Lua scripts?</p>