More changes from Red Storm port

- only call sched_yield if it exists
  - don't fail out if modex doens't work in ob1
  - bunch of fixes for Portals BTL
  - add cnos rml component
  - add NULL gpr component (should only be used if replica AND proxy
    fail to load)  

This commit was SVN r6629.

opal/runtime/opal_progress.c

@@ -237,7 +237,7 @@ opal_progress(void)
          * the processor is oversubscribed - this will result in a best-case
          * latency equivalent to the time-slice.
          */
-#ifndef WIN32
+#if !defined(WIN32) && defined(HAVE_SCHED_YIELD)
         /* TODO: Find the windows equivalent for this */
         sched_yield();
 #endif