Drop fees by 10x due to the persistently higher exchange rate.

The last fee drop was by 5x (from 50k satoshis to 10k satoshis)
in the 0.8.2 release which was about 6 months ago.

The current fee is (assuming a $500 exchange rate) about 5 dollar
cents. The new fee after this patch is 0.5 cents.

Miners who prefer the higher fees are obviously still able to
use the command line flags to override this setting. Miners who
choose to create smaller blocks will select the highest-fee paying
transactions anyway.

This would hopefully be the last manual adjustment ever required
before floating fees become normal.
Wallet locking fixes for -DDEBUG_LOCKORDER

Compiling with -DDEBUG_LOCKORDER and running the qa/rpc-test/ regression
tests uncovered a couple of wallet methods that should (but didn't)
acquire the cs_wallet mutext.

I also changed the AssertLockHeld() routine print to stderr and
abort, instead of printing to debug.log and then assert()'ing.
It is annoying to look in debug.log to find out which
AssertLockHeld is failing.
script: tighten multisig non-standard rules: do not relay pubkeys above 65 bytes
Merge pull request #3718 from jgarzik/pubkey-size

script: tighten multisig non-standard rules: do not relay pubkeys above 65 bytes
Test for walletbackup/walletdump RPC calls
Merge pull request #3700 from gavinandresen/backuptest

Test for walletbackup/walletdump RPC calls
Merge pull request #3305 from mikehearn/fee_drop

Drop fees by 10x due to the persistently higher exchange rate.
Merge pull request #3704 from gavinandresen/wallet_lock_fixes

Wallet locking fixes for -DDEBUG_LOCKORDER