* erasure-coding block data

* adjust error handling

* merkleize chunks and yield branches for each

* construction and proving of merkle branches

* port over to new GF(2^16) impl

* some tests for wrapped_shard

* handle extra byte from GF(2^16) better

* point to github dependency

* add issue link

* point to master for reed-solomon-erasure

* add missing license header

Test to fix wasm_builder 2.0.0

Feature/fixing unit tests

provide multisig runtime module.
this module' feature is similar to eth-parity multisig contract,
but now it only opens for genesis block config, not for public.
the operation step is flow:

1. a sender call deploy call to deploy a multisig account. the deploy would generate a multisig addr(accountid). this account is all same to the normal account.
2. the signer call execute call to do a transaction for thie multisig account, the execute would generate a multisig id for this multisig addr. now, it only support transfer chainx.
3. the signer call confirm call to sign for a multisig addr and id, when get enough sign, the transaction in execute would turely exec. notice the exec tx would fail.

other thing:
provide cxrml-support module to organize the common utils, has provide handle_fee_before/after and StorageDoubleMap

Tag recommitment

…lock-tokens-extrinsic

Allow multiple use of sudo_unlock_all_vesting_tokens