cmd/geth: include the error message on import failure

This reverts commit 7a5b571c.

This reverts commit c4de2893.

This reverts commit ba784bdf.

This implements a generic approach to enabling soft forks by allowing
anyone to put in hashes of contracts that should not be interacted from.
This will help "The DAO" in their endevour to stop any whithdrawals from
any DAO contract by convincing the mining community to accept their code
hash.

This fixes an issue if you wanted to test out code deployment rather
than running a piece of code with an argument. This solves it by adding
a --create flag that indicates the Create function should be used rather
than the Call function.

This also adds a statedb.commit call so that the proper state can be
dumped when requested using the --dump flag.

* use --port 0 to avoid p2p port conflicts
* use --maxpeers 0 so it doesn't connect to bootstrap nodes
* use geth.expectExit() to wait for termination

We used to have reporting of bad blocks, but it was disabled
before the Frontier release. We need it back because users
are usually unable to provide the full RLP data of a bad
block when it occurs.

A shortcoming of this particular implementation is that the
origin peer is not tracked for blocks received during eth/63
sync. No origin peer info is still better than no report at
all though.

Calls to 'personal' API should be excluded from console history because
they can be called with an account passphrase as argument. The check for
such calls was inverted and didn't work.

Also reduce log messages a little bit.