dumpwallet: produce a dump of all keys in a wallet, in a format
compatible with Bitcoin Wallet for Android and Multibit.
importwallet: import such a dump
Compute safe lower bounds on the birth times of all wallet keys. For
pool keys or keys with metadata, the actually stored birth time is
used. For all others, the birth times are inferred from the wallet
transactions.
This function finds all keys affected by a particular output script,
supporting everything ExtractDestinations supports (pay-to-pubkey,
pay-to-pubkeyhash, multisig) and recurses into subscripts (P2SH).
In case no database exists yet, and -txindex(=1) is passed, we currently first
check whether fTxIndex differs from -txindex (and ask the user to reindex in
that case), and only afterwards initialize the database. By swapping these
around (the initialization is a no-op in case the database already exists),
we allow it to be born in txindex mode, without warning.
That also means we don't need to check -reindex anymore, as the wiping/reinit
of the databases happens before checking.
Refactor keytime:
* Key metadata is kept in a CWallet::mapKeyMetadata (std::map<CKeyId,CKeyMetadata>).
* When generating a new key, time is put in that map, and new key is written.
* AddKeyPubKey and AddCryptedKey do not take a creation time argument, but instead
pull it from that map, if it exists there.
Bugfix:
* AddKeyPubKey and AddCryptedKey in CWallet didn't override the CKeyStore
definition anymore. This is fixed, as they no longed need the nCreationTime
argument now.
Also a few related other changes:
* Metadata can be overwritten.
* Only GenerateNewKey calls GetTime(), as it's the only place where we know for
sure a key was not constructed earlier.
* When the nTimeFirstKey is known to be inaccurate, it is set to the value 1
(instead of 0, which would mean unknown).
* Use CPubKey instead of std::vector<unsigned char> where possible.
Pieter Wuille