remove unused IsMatureSyncCheckpoint()
increase checkpoint span
Move getinfo to rpcnet.cpp

Where to place `getinfo` is a difficult issue
as it shows information from the wallet, net and
block chain. However, I moved it out of rpcwallet
as the command needs also to be available without
wallet.

Conflicts:
	src/rpcnet.cpp
	src/rpcwallet.cpp
Move CAddrDB frrom db to net

This was a leftover from the times in which
peers.dat depended in BDB.

Other functions in db.cpp still depend on BerkelyDB,
to be able to compile without BDB this (small)
functionality needs to be moved to another file.

Conflicts:
	src/db.cpp
	src/db.h
	src/net.cpp
	src/net.h
Move CCryptoKeyStore to crypter.cpp

This breaks the dependency on crypter for disable-wallet builds.

Conflicts:
	src/Makefile.am
	src/crypter.cpp
	src/keystore.h
Delimit code with #ifdef ENABLE_WALLET

Delimit all code that uses the wallet functions
in implementation files that conditionally use the wallet.

Conflicts:
	src/init.cpp
	src/rpcnet.cpp
	src/rpcrawtransaction.cpp
	src/rpcserver.cpp
	src/test/rpc_tests.cpp
	src/test/test_bitcoin.cpp
Add USE_WALLET option to makefiles

Make it possible to build daemon without wallet
(and thus without BDB) so that it only functions as node.
add new RPC implementation file `rpcmisc.cpp`

Conflicts:
	src/Makefile.am
Move `getinfo` from rpcnet to rpcmisc

`getinfo` is a general info method which shows information
from multiple sources, it doesn't belong in rpcnet.cpp or
any of the other current RPC implementation files.

Conflicts:
	src/rpcnet.cpp
Move `settxfee` from rpcblockchain to rpcwallet

`settxfee` only affects the wallet, not the block chain.

Conflicts:
	src/rpcblockchain.cpp
	src/rpcserver.cpp
	src/rpcwallet.cpp
Move `nTransactionFee` from main.cpp to wallet.cpp

Transaction fee is only used by the wallet.
No need for it to be in main.cpp.

Conflicts:
	src/init.cpp
	src/main.cpp
	src/main.h
	src/qt/bitcoin.cpp
	src/qt/optionsmodel.cpp
	src/rpcmisc.cpp
	src/wallet.cpp
	src/wallet.h