Problem::Evaluate implementation.

1. Add Problem::Evaluate and tests.
2. Remove Solver::Summary::initial/final_*
3. Remove Solver::Options::return_* members.
4. Various cpplint cleanups.

Change-Id: I4266de53489896f72d9c6798c5efde6748d68a47
diff --git a/internal/ceres/trust_region_strategy.h b/internal/ceres/trust_region_strategy.h
index 391da97..f150594 100644
--- a/internal/ceres/trust_region_strategy.h
+++ b/internal/ceres/trust_region_strategy.h
@@ -52,7 +52,7 @@
 // radius to scale the damping term, which controls the step size, but
 // does not set a hard limit on its size.
 class TrustRegionStrategy {
-public:
+ public:
   struct Options {
     Options()
         : trust_region_strategy_type(LEVENBERG_MARQUARDT),