title: Searching history using opengrok
body: <p>i have been working on OPENGROK for searching through my SVN code repository. It requires a checked out version of the repository to index it.
  I have been able to achieve is searching through the repository when i have checked out version on my system.
  Where i am stuck is when i try to search through History of the repository . i am not getting any help on it. 
  Can anyone suggest me what to do.
  More over if i want to update the indexes instead of creating new ones all the time how to achieve it.
  Any contribution will be a huge help to me.
  Thanks for your time and help.</p>