title: different levels in code igniter?
body: <p>im all new to framework.</p>
  
  <p>so the structure of code igniter looks like:</p>
  
  <p>system
  system/application</p>
  
  <p>the system folder is code igniter's base folder right? so if they in the future releases a new version i just put application in the new system folder and its upgraded right?</p>
  
  <p>does this mean that i shouldn't put new files and so on in the system folder? cause some code could be used for other applications and i want to put them under the current application im developing, not inside the application folder.</p>
  
  <p>i want my application's classes to extend my base system's classes which in turn extend code igniter's base system class.</p>
  
  <p>so there are 3 levels. so how could i accomplish this? where to put the system level between CI and my application?</p>