Nest all namespaces

The compiler supports this now.  We can type less going forward.
No functional changes.

Signed-off-by: Stephan Pleines <pleines.stephan@gmail.com>
Change-Id: I29d6fa4f9aacc0e381f1a7637294db0392466995
diff --git a/y2014/control_loops/claw/claw.cc b/y2014/control_loops/claw/claw.cc
index 2fb93b4..39ee7a4 100644
--- a/y2014/control_loops/claw/claw.cc
+++ b/y2014/control_loops/claw/claw.cc
@@ -40,9 +40,7 @@
 // If a claw runs up against a movable limit, move both claws outwards to get
 // out of the condition.
 
-namespace y2014 {
-namespace control_loops {
-namespace claw {
+namespace y2014::control_loops::claw {
 
 using ::frc971::HallEffectTracker;
 using ::frc971::control_loops::DoCoerceGoal;
@@ -1019,6 +1017,4 @@
   was_enabled_ = enabled;
 }
 
-}  // namespace claw
-}  // namespace control_loops
-}  // namespace y2014
+}  // namespace y2014::control_loops::claw