callback with server headers for wallet coin name

client.rpc.call('getinfo', [], console.log,function(){});
result : {}, {server: 'nexuscoin-json-rpc/v0.8.6-12-g4d83b6e-dirty-beta'}
remove unused deprecated commands module
Merge branch 'patch-1' of https://github.com/shimondoodkin/node-bitcoin into shimondoodkin-patch-1
add tests for response headers to callback
update readme and changelog with new features