carbon copy of namecoin mainnet

the next commit will have the changes to become testnet
various changes to enable namecoin testnet

testnet uses irc channel #namecoinTEST without any numbers at the end,
getinfo now returns testnet:true, auxpow at height 4042
rpcuser/password and coinexplorer name rpc calls

known bug:
rpc user:pass needs to be in lowercase base64
v:a -> djph

new feature:
coinexplorer have got new rpc calls to handle names in the namecoin
chains
merge rpc pass known bug and coinexplorer name rpc calls
-coinexplorer name rpc calls, +chain specific ignoring of rules to enable sync

now this code should not interfere with any other chain then namecoin
testnet
symlink to +namecointestd.conf and makefile to create namecointestd
Fixed issue with connecting to same server multiple times (in case of using the —connect option)
Changed the “MINIMAL” option to actually purge on every new block commit.
purge depth, --version --help and rpc help

persistence was warning when purge depth is 1 using FULL setting (zero),
--version and --help now works, and RPC method "help" is no longer
intercepted wrongly
Merge branch 'master' of github.com:libcoin/libcoin into namecoin-testnet-beta
Merge branch 'namecoin-testnet-beta' into name-list