Test updates

solidity compiler and contract metadocs integration

xeth, core, event/filter, rpc: new block and transaction filters

Update ethash deps (more build fixes, tests)

* common/compiler: solidity compiler + tests
* rpc: eth_compilers, eth_compileSolidity + tests
* fix natspec test using keystore API, notice exp dynamically changes addr, cleanup
* resolver implements registrars and needs to create reg contract (temp)
* xeth: solidity compiler. expose getter Solc() and paths setter SetSolc(solcPath)
* ethereumApi: implement compiler related RPC calls using XEth - json struct tests
* admin: make use of XEth.SetSolc to allow runtime setting of compiler paths
* cli: command line flags solc to set custom solc bin path
* js admin api with new features debug and contractInfo modules
* wiki is the doc https://github.com/ethereum/go-ethereum/wiki/Contracts-and-Transactions

Fix block tests genesis block total difficulty

Last minute p2p fixes

p2p/discover: sha3-based node distance

core: transaction pool fixes & resending transactions

Ethash reloaded

jsre: support for setTimeout, sendAsync 

The previous metric was pubkey1^pubkey2, as specified in the Kademlia
paper. We missed that EC public keys are not uniformly distributed.
Using the hash of the public keys addresses that. It also makes it
a bit harder to generate node IDs that are close to a particular node.

added and eval queue for serializing JSRE vm execution