Add some missing headers to ceres.h

https://github.com/ceres-solver/ceres-solver/issues/423

Change-Id: I568aeda83b91a4d5a12a3f271078535610c4ad44

include/ceres/ceres.h

diff --git a/include/ceres/ceres.h b/include/ceres/ceres.h
index 64ffb99..6e077cc 100644
--- a/include/ceres/ceres.h
+++ b/include/ceres/ceres.h
@@ -36,12 +36,17 @@
 
 #include "ceres/autodiff_cost_function.h"
 #include "ceres/autodiff_local_parameterization.h"
+#include "ceres/conditioned_cost_function.h"
+#include "ceres/context.h"
 #include "ceres/cost_function.h"
 #include "ceres/cost_function_to_functor.h"
 #include "ceres/covariance.h"
 #include "ceres/crs_matrix.h"
 #include "ceres/dynamic_autodiff_cost_function.h"
+#include "ceres/dynamic_cost_function.h"
+#include "ceres/dynamic_cost_function_to_functor.h"
 #include "ceres/dynamic_numeric_diff_cost_function.h"
+#include "ceres/gradient_checker.h"
 #include "ceres/gradient_problem.h"
 #include "ceres/gradient_problem_solver.h"
 #include "ceres/iteration_callback.h"
@@ -49,6 +54,7 @@
 #include "ceres/local_parameterization.h"
 #include "ceres/loss_function.h"
 #include "ceres/numeric_diff_cost_function.h"
+#include "ceres/numeric_diff_options.h"
 #include "ceres/ordered_groups.h"
 #include "ceres/problem.h"
 #include "ceres/sized_cost_function.h"