title: All Java Files becomes red marked as error. but project build successfully
body: <p>I am using <code>android studio 1.0</code>. I am developing a small android application. When i was editing the code in one of my <code>java</code> file in android studio, power cut happened. 
  After power came, i open the android studio and open my project, all files in the java folder marked as red indicationg error. 
  but the projects build successfully. when i <code>sync with gradle</code>. 
  it also done successfully. and perfectly runs in the device after launced the app in my phone.. but the red mark not disappear 
  even i close the project and reopen. If i create new project also, the same things happen again.
       i can't understand what's happened. i also tried re install my <code>jdk 1.7</code><br>
  Can anyone help me, how to fix this bug. please give exact solution. i don't like suggestions like to re install android studio</p>