Clean up documentation and code examples in public headers

- Fix code examples in comments across autodiff_cost_function.h,
  numeric_diff_cost_function.h, conditioned_cost_function.h,
  cubic_interpolation.h, dynamic_cost_function_to_functor.h,
  dynamic_numeric_diff_cost_function.h, gradient_problem.h,
  loss_function.h, and numeric_diff_first_order_function.h.
- Fix function_tolerance sign and gradient_tolerance formula in
  solver.h, gradient_problem_solver.h, tiny_solver.h, and types.h.
- Fix outdated option/parameter references in comments across
  gradient_checker.h, gradient_problem_solver.h, numeric_diff_options.h,
  solver.h, and types.h.
- Fix include path for ceres/internal/parameter_dims.h and
  static_assert message in sized_cost_function.h.
- Fix typos, duplicate words, grammar, and capitalization in header
  comments.

Change-Id: I11cb8fca41117654bf872196c97bd6b007cda637