title: luaopen_my_example undefined after compiling swig wrapper
body: <p>I'm just now diving into SWIG as a means for creating Lua bindings, and I've hit a snag. I made my interface file and built a shared object file from it all without any problems. However, when I run Lua and try to require the shared object, I get the following: </p>
  
  <pre>
  Lua 5.1.4  Copyright (C) 1994-2008 Lua.org, PUC-Rio
   require("my_example")
   error loading module 'my_example' from file './my_example.so':
  
          ./my_example.so: undefined symbol: luaopen_my_example
  </pre>
  
  <p>stack traceback:</p>
  
  <pre>
  [C]: ?
  
  [C]: in function 'require'
  
  stdin:1: in main chunk
  
  [C]: ?
  </pre>
  
  <p>I can't seem to find anything online describing this situation, so I thought I'd post here. Are there any SWIG Gurus out there? The class I'm wrapping is a few thousand lines long (and proprietary) or I'd post it here.</p>
  
  <p>Thanks! :D</p>