V1.6.2 Minor RPC improvements

Small RPC and GuldenD fixes for services that are integrating the new 1.6.x account systems.
Bring back two RPC commands that were removed in initial 1.6 release, these commands have been modified to work with the Gulden accounts system.

getaccount "Guldenaddress"
getaddressesbyaccount "account"

1.6.1

New user interface with drastic improvements over the old user interface.
Ticker/Exchange rate integration into app.
In wallet support for buying coins with euro via nocks.
New 'account based' wallet internals.
New in wallet buy support for bitcoin and IBAN via nocks API.
Full support for BIP33 and BIP44 HD wallet standards with mnemonics.
Implement support for synchronised mobile accounts.
Update to upstream bitcoin 0.13 codebase providing numerous bug fixes and improvements.
Improve the checkpointing code, fix a checkpoint corruption issue that some users were experiencing.
Change 'rpconlylistsecuredtransactions' to be on by default.

v1.5.5

Installers for old 1.5.5 release.

1.5.0 release

New updated codebase based on bitcoin 0.10/0.11
Impement a new difficulty adjustment algorithm named DELTA.