Refactored checked_convert_to_int to use number_as_integer.
Made datum serialization format use datum_serialized_type_t instead of datum_t::type_t.
Merge branch 'sam_1427' into sam_1426
Made datum serialization use varint serialization for numeric datums that are integral.
Merge branch 'next' into sam_1426
Removed unused number_as_integer declaration in datum.hpp.
Made meta_op_t be meta_op_term_t.
Got rid of is_deterministic_impl.
Removed the backtrace_t::push_back helper function.
Removed unused dummy_frames argument from fourth exc_t constructor.
Removed unused dummy_frames parameter from runtime_check and the second exc_t constructor.
Turned runtime_check into runtime_fail.
Removed a bunch of unnecessary unreachable()s.
Used UNUSED in a place.
Put r_sanity_check conditional in macro.
Made datum_term_t check that it has a valid protobuf.
Removed pb_rcheckable_t constructor that takes a Term.
Made datum_stream_t and eager_datum_stream_t constructors be protected.
Made func_t constructor be protected.
Made val_t constructor not take scope_env_t, take env_t instead.