When a chain reorganisation occurs we collect the logs that were deleted
during the chain reorganisation. The removed logs are posted to the
event mux indicating that those were deleted during the reorg.

This removes the burden on a single object to take care of all
validation and state processing. Now instead the validation is done by
the `core.BlockValidator` (`types.Validator`) that takes care of both
header and uncle validation through the `ValidateBlock` method and state
validation through the `ValidateState` method. The state processing is
done by a new object `core.StateProcessor` (`types.Processor`) and
accepts a new state as input and uses that to process the given block's
transactions (and uncles for rewords) to calculate the state root for
the next block (P_n + 1).

Log filtering is now using a MIPmap like approach where addresses of
logs are added to a mapped bloom bin. The current levels for the MIP are
in ranges of 1.000.000, 500.000, 100.000, 50.000, 1.000. Logs are
therefor filtered in batches of 1.000.

Due to a rebase this probably got overlooked / ignored. This fixes the
issue of a block insertion never writing the last block.

* Renamed ChainManager to BlockChain
* Checkpointing is no longer required and never really properly worked
when the state was corrupted.

This PR solves an issue with the chain manager posting a
`RemovedTransactionEvent`, the tx pool will try to
acquire the chainmanager lock which has previously been locked prior to
posting `RemovedTransactionEvent`. This results in a deadlock in the
core.

The test genesis block was not written properly, block insertion failed
immediately.

While here, fix the panic when shutting down "geth blocktest" with
Ctrl+C. The signal handler is now installed automatically, causing
ethereum.Stop to crash because everything is already stopped.

Added a `Difference` method to `types.Transactions` which sets the
receiver to the difference of a to b (NOTE: not a **and** b).

Transaction pool subscribes to RemovedTransactionEvent adding back to
those potential missing from the chain.

When a chain re-org occurs remove any transactions that were removed
from the canonical chain during the re-org as well as the receipts that
were generated in the process.

Closes #1746

* changed stack and removed stack ptr. Let go decide on slice reuse.

When a user runs a freshly setup geth w/o a database initialised the
default genesis block is decoded and inserted in to the database.

The running flag will determine whether the chain manager is still
running or not. This will prevent the quit channel from being closed
twice resulting in a panic. This PR should fix this issue.

Closes #1559

Genesis release. Closes #1402

Conflicts:
	cmd/geth/main.go

I forgot to update one instance of "go-ethereum" in commit 3f047be5.

All code outside of cmd/ is licensed as LGPL. The headers
now reflect this by calling the whole work "the go-ethereum library".

Added PutBlockReceipts; storing receipts by blocks. Eventually this will
require pruning during some cleanup cycle. During forks the receipts by
block are used to get the new canonical receipts and transactions.

This PR fixes #1473 by rewriting transactions and receipts from the point
of where the fork occured.

Implemented the --genesis flag thru which we can set a custom genesis
block, including the official Ethereum genesis block.