complex: derive Eq
complex: derive Eq

Fixes #245.

rust-num/num-traits,rust-num/num-bigint,rust-lang/num,rust-num/num-traits,rust-num/num,rust-num/num-bigint,DonSheddow/num,DonSheddow/num,rust-lang/num,vks/num,koverstreet/num,koverstreet/num,rust-num/num-integer,rust-num/num,rust-num/num-integer,vks/num