title: Systematically resolve conflicting styles in css
body: <p>I have some stylesheets from different sources in my web project. I want to harmonize them. 
  Some styles I need from the one, some from the other. 
  Is there a tool or method how to systematically resolve style conflicts?
  I tried IE8 developer tool, and yes, it is possible to view conflicts at the level of each element. 
  But I have many elemens, so if I do it element by element I think this takes too long. 
  Theoretically there could be a tool that shows conflicts of two css files at design time?!? I think this would save me a lot of time.</p>