[Checkers] langtools repositories

[Mahmood Ali]

Greetings Michael,

I have set the following repositories:
  - $pag/projects/annotations/langtools-proto   repo with our features
  - $pag/projects/annotations/langtools         main development repo
  - hg.openjdk.java.net/.../langtools           open jdk repo

I added a hg hook to pag langtools so any changes that get applied to  
it will be pushed as well to langtools-proto automatically.  It would  
fail if there is a conflict, but the likelyhood of that happening is  
very slim.

My current process is develop locally, push all changes to pag  
langtools, and every now and then, push the changes to openjdk  
langtools.  I hope that eliminates the need for you to update multiple  
times.

Regards,
Mahmood