opentxs-crypto: fix -Wredundant-decls
Fix command showaccounts

OTAPI_Wrap::GetAccountWallet_Name is used to get account wallet name. The name could be empty so name emptiness should not be used for testing account existence.

Closes #256
Merge pull request #271 from toxeus/fixRedundantDecls

opentxs-crypto: fix -Wredundant-decls
Merge pull request #275 from mhamrle/issue_256_showaccounts

Fix command showaccounts
OTString: move fwrite_string() into caller

It doesn't make sense to have a separate function which is
used only in one place.
Merge pull request #278 from toxeus/removeFwriteString

OTString: move fwrite_string() into caller
ZMQ: Send/Receive code cleanup.
Merge pull request #279 from benma/zmq

ZMQ: Send/Receive code cleanup.
Remove useless includes
Remove unused param from UserCmdGetContract
Merge pull request #277 from mhamrle/small_improvements

Small improvements
MintLucre: remove commented out code
MintLucre: cleanup #ifdef statements
MintLucre: move SetMonitor() code to caller

SetMonitor() is a Windows only helper function but not easily
recognizable as such. Moreover, it uses the same name as
functions provided by the lucre library which is confusing.
Both problems are addressed by this patch.
Merge pull request #280 from toxeus/cleanupMintLucre

MintLucre: some cleanup
opentxs-core: remove unused functions
Merge pull request #281 from toxeus/removeUnusedFunctions

opentxs-core: remove unused functions
Removed unused OTPayload::GetEnvelope, GetMessagePayload, ReadBytesFrom.

blub
Refactored OTData::Release() (does not need to be virtual).
Removed SetPayloadSize (it's the same as SetSize).