Improve readability of recent rate limiter changes.

This commit builds on the recent limiter updates.  The recent changes
introduced a new function named calcTxFee which could easily be confused
with calculating the fees of the transaction rather than its intended
purpose of calculating the minimum transaciton relay fee.

Rather than taking that approach, this commit instead renames the existing
function to calcMinRequiredTxRelayFee and uses a consistent variable name
for the serialized size of a transaction.  It then moves the check for
whether or not the check should be applied based on the serialized size of
the transcation and block priority to the call site.

This approach also has the benefit of avoiding two calls to the
calculation function since it's a local at the call site.

ok @jrick, @dajohi
Always show help on help flag.

This commit resolves a minor issue where an error in the config file would
prevent the help from being shown until the config file error was
resolved.

This results in the following behavior:

- With a malformed header:
  $ ./btcd
  Error parsing config file: ~/btcd/btcd.conf:14: malformed section header
  Use btcd -h to show usage
- With an invalid option:
  $ ./btcd
  Error parsing config file: unknown option: bogus
  Use btcd -h to show usage
- Invoking help with an error in the config file:
  $ ./btcd -h
  Usage:
  ...
- Invoking with an invalid command line option:
  $ ./btcd --bogus=bogus
  unknown flag `bogus'
  Use btcd -h to show usage

ok @jrick
Add signrawtransaction to btcctl.
Display JSON when using btcctl's signrawtransaction.
Implement verifymessage RPC.
Add testnet3 dnsseed testnet-seed.bitcoin.schildbach.de
Use Errorf when using formatting directives.

Found by go vet.
Add getnetworkinfo support to btcctl.

ok @jrick
Use the new bloom Reload API.

This fixes a race caught by the go race detector.
ok @jrick
Pass the correct types for signrawtransaction.
Make btcctl errcheck clean.

This commit explicitly ignores errors that were already intentionally
ignored in btcctl by using an _ to make the errcheck utility happy.  It is
also nice to make it explicit that the error is being ignored
intentionally rather than leave questions of whether it was accidentally
forgotten.
btcctl: Fix createrawtransaction amounts.

These were being counted in satoshis, when the JSON object should be
containing JSON numbers, counted in BTC.
Fix some typos throughout repo.
Reject transactions with too many signature operations.

This matches recent changes in bitcoin core.
Match error names to btcdb updates.
Use Warnf when processing directives.
Update sample config file.

This commit adds a couple of options which were not details in the sample
config file.  It also fixes a couple of typos and makes the example default
maxpeers setting in the config file match the actual default used in btcd.
Remove transactions from orphan pool.

This change removes transactions from a newly connected block
from the orphan pool if they exist.  Additionally, any orphan
transactions that are no longer orphan transactions are moved
to the mempool and inv'd to the currently connected peers.
Prepare for release 0.9.0.
Changed TxIn.PreviousOutpoint to TxIn.PreviousOutPoint after btcwire API change.