Collator for the "adder" (formerly basic-add) parachain and various small fixes (#438)

* update basic_add wasm

* wasm feature and collator feature

* move test parachains around a little

* fix wasm build for basic_add

* move basic_add to adder, introduce README

* minimal basic_add collator

* ensure collator messages are sent in the right order

* more logging

* route consensus statements to all peers

* minor bugfixes for parachains

* genesis builder accounts for parachain heads

* fix parachains tests

* targets for txpool

* tweak runtime + collator

* fix version in adder-collator

* consistency for overflowing

* adjust comment

* fix stable test run

* remove dummy registration test

* final grumbles

polkadot/parachain/tests/adder.rs

@@ -76,7 +76,7 @@ impl Decode for BlockData {
 	}
 }
 
-const TEST_CODE: &[u8] = include_bytes!("res/basic_add.wasm");
+const TEST_CODE: &[u8] = include_bytes!("res/adder.wasm");
 
 fn hash_state(state: u64) -> [u8; 32] {
 	::tiny_keccak::keccak256(state.encode().as_slice())