Lint and other fixes from William Rucklidge

Change-Id: Ic18561a5cdadccc75e97818fa4422bb5d9d43df9
diff --git a/include/ceres/solver.h b/include/ceres/solver.h
index 854df2a..8bf87f9 100644
--- a/include/ceres/solver.h
+++ b/include/ceres/solver.h
@@ -603,6 +603,8 @@
     int num_unsuccessful_steps;
     int num_inner_iteration_steps;
 
+    // All times reported below are wall times.
+
     // When the user calls Solve, before the actual optimization
     // occurs, Ceres performs a number of preprocessing steps. These
     // include error checks, memory allocations, and reorderings. This