Made term_t::eval be const.
Removed unused and undefined function declaration op_term_t::consume.
Marked a method const, whatever.
Removed pointless std::move return.
Made args_t explicitly noncopyable.
Fixed trivial style problems.
Merge branch 'next' into sam_2156_env_4
Renamed args_t to arg_terms_t.
Added unused args_t type.
Made eval_impl take an args_t (that is not actually reentrant yet).
Removed RSI comment.  bounded_op_term_t optargs cannot be static because they use rfail.
Made make_obj_term_t not inherit from op_term_t.
Removed dead make_obj-specific stuff in op_term_t and optargspec_t.
Made helpers all_are_deterministic, accumulate_all_captures.
Made make_obj_term_t error message match old "Duplicate object key" string in old op_term_t code.
Made some http_term_t methods be static.
Merge branch 'next' into sam_2156_env_4
Added comments about the state of arg0 in term_eval.
Marked the const fields of arg_terms_t as const.
Added assertion in maybe_grouped_data.