Fixed incorrect reference to subversion rather than mercurial.

docs/README.txt

@@ -35,10 +35,9 @@ There are four scripts in the docs folder.
  - testenv:  This script tests your environment for all the needed utilities.
 	     Run it and it should tell you what else you need to install. 
 	     Note that the htmlify utility is something I wrote and is in
-	     dlib's svn repository in the trunk/tools/htmlify folder.  You 
-	     should build and install it.  (go into that folder, make a 
-	     subfolder called build, then cd into build and say:  
-	     	"cmake ..; make; sudo make install".  
+	     dlib's repository in the tools/htmlify folder.  You should build 
+	     and install it.  (go into that folder, make a subfolder called 
+	     build, then cd into build and say:  "cmake ..; make; sudo make install".  
 	     You will need to install cmake if you don't have it already)
 
  - makedocs: This remakes all the HTML documentation by pulling files out