Minor upstream file changes

CONTRIBUTING.md

@@ -48,7 +48,7 @@ Ready to submit? Perform the checklist below:
    the team prior to starting work.
 6. Are my commit messages descriptive?
 
-You should be aware of `git rebase`.
+You should be aware of [`git rebase`](http://learn.github.com/p/rebasing.html).
 It allows you to modify existing commit messages, and combine, break apart, or
 adjust past changes.
 
@@ -66,4 +66,4 @@ This is **EXTREMELY BAD:**
     if(var.func( param1, param2 ))
     {
         // do things
-    }
+    }