title: Android library project some class id in R.java mismatch
body: <p>I have 2 projects A and B. I have set project A as a library project and I have added its dependency in project B. Now when I build my Project B, I find that R.java includes id's of controls/layouts from both A and B.</p>
  
  <p>Now I compare the R.java files of project A and B. Initially the class id of say a particular widget is same in both R.java files.<br>
  Now I add a new control (say a Button) in Project B. If I check the R.java files now, then there is a mismatch between the class ids of same widget in Project A and B.</p>
  
  <p>Due to this I am getting <code>classNotfound</code> and <code>classcastexception</code> at runtime. Has anyone faced a similar issue? Its very frustrating!</p>