* core: Added GasPriceChange event
* eth: When one of the DB flush methods error a fatal error log message
is given. Hopefully this will prevent corrupted databases from
occuring.
* miner: remove transactions with low gas price. Closes#906, #903
* 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
Chain reorgs weren't properly handled when a chain was further ahead.
Previously we'd end up with mixed chains in our canonical numbering
sequence. Added test for this type of forking.
```
/-o-o-o A
o-C-+
\-o-o-o-o B
```
Ends up with with C A1, A2, A3, B4
* Changed CalcGasLimit to no longer need current block
* Added a gas * price + value on tx validation
* Transactions in the pool are now re-validated once every X
Transactions are now propagated to peers from which we have not yet
received the transaction. This will significantly reduce the chatter on
the network.
Moved new mined block handler to the protocol handler and moved
transaction handling to protocol handler.
Implemented a new transaction queue. Transactions with a holes in their
nonce sequence are also not propagated over the network.
N: 0,1,2,5,6,7 = propagate 0..2 -- 5..N is kept in the tx pool
You can now specify `null` as a way of saying "not interested in this
topic, match all". core.Filter assumes the zero'd address to be the
wildcard. JSON rpc assumes empty strings to be wildcards.
