Use the raw transactions API to send coins received on a particular
address (or addresses).

Depends on jsonrpc

Usage:

spendfrom.py --from=FROMADDRESS1[,FROMADDRESS2] --to=TOADDRESS --amount=amount \
             --fee=fee --datadir=/path/to/.bitcoin --testnet --dry_run

With no arguments, outputs a list of amounts associated with addresses.

With arguments, sends coins received by the FROMADDRESS addresses to the TOADDRESS.

You may explictly specify how much fee to pay (a fee more than 1% of the amount
will fail,  though, to prevent bitcoin-losing accidents). Spendfrom may fail if
it thinks the transaction would never be confirmed (if the amount being sent is
too small, or if the transaction is too many bytes for the fee).

If a change output needs to be created, the change will be sent to the last
FROMADDRESS (if you specify just one FROMADDRESS, change will go back to it).

If --datadir is not specified, the default datadir is used.

The --dry_run option will just create and sign the the transaction and print
the transaction data (as hexadecimal), instead of broadcasting it.

If the transaction is created and broadcast successfully, a transaction id
is printed.

If this was a tool for end-users and not programmers, it would have much friendlier
error-handling.