This commit adds the feature bit and additional fields
required in `open_channel` and `accept_channel` wire
messages for `option_upfront_shutdown_script`.
In this commit, we export the ReadElements and WriteElements functions.
We do this as exporting these functions makes it possible for outside
packages to define serializations which use the BOLT 1.0 wire format.
In this commit, we begin implementing the latest spec change to reduce
the attack surface on online channels. In this commit, we introduce a
distinct HTLC base point which will be used to sign the second-level
HTLC transactions for each active HLTC on the commitment transaction of
the remote node. With this, we allow the commitment key to remain
offline, as it isn’t needed in routine channel updates, unless we need
to go to chain.
In this commit we add a new type to the lnwire package: FundingFlag.
This type will serve as an enum to describe the possible flags that can
be used within the ChannelFlags field in the OpenChannel struct.
We also define the first assigned flag: FFAnnounceChannel, which
indicates if the initiator of the funding flow wishes to announce the
channel to the greater network.
This commit adds the new set of single funder messages from the
specification. As a result, after this commit and a follow up, all of
our messages will directly line up with those that are detailed within
the specification.
The new set of funding messages are very similar to our prior ones,
aside from the main difference of the addition of several channel level
constraints that give nodes control over their exposure, throughput,
and other values.
