* read head-data directly out of WASM memory
* implement ext_post_message for parachain WASM
* further refactoring of the parachain module
* add externalities error type
* accumulate posted messages when validating parachain candidate
* define Extrinsic type in primitives
* availability-store: store extrinsic data
* compute extrinsic and check against candidate
* add some egress queue tests
* grumbles & substrate update
* ensure everything builds
* 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