Reduced big int allocation by making stack items modifiable. Instead of
adding items such as `common.Big0` to the stack, `new(big.Int)` is
added instead. One must expect that any item that is added to the stack
might change.

Reduced the amount of state copied that are required by N calls by doing
a balance check prior to any state modifications.

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

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".

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

* Update => SyncIntermediate
* Added SyncObjects

SyncIntermediate only updates whatever has changed, but, as a side
effect, requires much more disk space.

SyncObjects will only sync whatever is required for a block and will not
save intermediate state to disk. As drawback this requires more time
when more txs come in.

Disassociates hardcoded tests to skip when running via CLI. Tests still
skipped when running `go test`