Build all sources with exported symbols as part of Ceres

Several sources implementing exported classes of the public API were
listed among the internal sources, contrary to the documented split
between exported and internal sources.

Move them to the exported sources.

Change-Id: I6543d33a247367ec8bfd54dc5b13ab38202e1939

internal/ceres/CMakeLists.txt

diff --git a/internal/ceres/CMakeLists.txt b/internal/ceres/CMakeLists.txt
index 61092b7..8ab92e2 100644
--- a/internal/ceres/CMakeLists.txt
+++ b/internal/ceres/CMakeLists.txt
@@ -68,8 +68,17 @@
 # sorted in lexicographical order.
 set(CERES_EXPORTED_SRCS
     c_api.cc
+    conditioned_cost_function.cc
+    context.cc
+    cost_function.cc
+    covariance.cc
+    dynamic_cost_function_to_functor.cc
+    evaluation_callback.cc
+    first_order_function.cc
     gradient_checker.cc
     gradient_problem.cc
+    gradient_problem_solver.cc
+    iteration_callback.cc
     loss_function.cc
     manifold.cc
     normal_prior.cc
@@ -166,13 +175,9 @@
     compressed_col_sparse_matrix_utils.cc
     compressed_row_jacobian_writer.cc
     compressed_row_sparse_matrix.cc
-    conditioned_cost_function.cc
-    context.cc
     context_impl.cc
     coordinate_descent_minimizer.cc
     corrector.cc
-    cost_function.cc
-    covariance.cc
     covariance_impl.cc
     cuda_block_sparse_crs_view.cc
     cuda_partitioned_block_sparse_crs_view.cc
@@ -189,22 +194,17 @@
     dogleg_strategy.cc
     dynamic_compressed_row_jacobian_writer.cc
     dynamic_compressed_row_sparse_matrix.cc
-    dynamic_cost_function_to_functor.cc
     dynamic_sparse_normal_cholesky_solver.cc
     eigensparse.cc
-    evaluation_callback.cc
     evaluator.cc
     event_logger.cc
     fake_bundle_adjustment_jacobian.cc
     file.cc
-    first_order_function.cc
     function_sample.cc
     gradient_checking_cost_function.cc
-    gradient_problem_solver.cc
     implicit_schur_complement.cc
     inner_product_computer.cc
     is_close.cc
-    iteration_callback.cc
     iterative_refiner.cc
     iterative_schur_complement_solver.cc
     levenberg_marquardt_strategy.cc