switched from fitpc/atom to prime/linux

Also removed a few old things that had nothing reasonable to be changed
to.
diff --git a/aos/common/once-tmpl.h b/aos/common/once-tmpl.h
index 9b9c8c5..9e3ebfe 100644
--- a/aos/common/once-tmpl.h
+++ b/aos/common/once-tmpl.h
@@ -9,7 +9,7 @@
 // It doesn't use pthread_once, because Brian looked at the pthreads
 // implementation for vxworks and noticed that it is completely and entirely
 // broken for doing just about anything (including its pthread_once). It has the
-// same implementation on the atom for simplicity.
+// same implementation under linux for simplicity.
 
 namespace aos {