This commit modifies the code to choose sane defaults for the backing
arrays for slices that involve a lot of appends such block locators, hash
processing, and needed transactions. This is an optimization to avoid
the overhead of growing the backing arrays and copying the data multiple
times in the most common case. This also prevents a leak in Go GC which
will likely ultimatley be fixed, but the efficiecy gains alone are worth
the change.
Rather than removing disconnected transactions from the node viewpoint
transaction store, clear the entry instead. This is needed for the
connect code to update transactions that were removed on the other side of
a chain fork.
This commit updates the calls into btcutil, btcscript, and btcwire for the
latest API changes which remove the need for the protocol version for
serialization and deserialization of blocks and transactions.
It is acceptable for a transaction input in a block to reference the
output of another transaction in the same block only if the referenced
transaction comes before the transaction referencing it.
