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.
Win32: use a more modern API call in FileCommit()

- this seems to be a more recent API call and also supports e.g. SMB3,
  ReFS, which is not guaranteed for commit_()
- link to MSDN: http://msdn.microsoft.com/en-us/library/windows/desktop/aa364439%28v=vs.85%29.aspx
Adds additional zero checks for setCompact
 These encoded values should all decode to zero

   Positive Numbers
    0x01003456 (1 byte  0x00)
    0x02000056 (2 bytes 0x0000)
    0x03000000 (3 bytes 0x000000)
    0x04000000 (4 bytes 0x000000_00)

   Negative Numbers
    0x00923456 -(0 bytes, so zero)
    0x01803456 -(1 byte  0x00)
    0x02800056 -(2 bytes 0x0000)
    0x03800000 -(3 bytes 0x000000)
    0x04800000 -(4 bytes 0x000000_00)
Don't store or send side-chain blocks lower than last checkpoint.
Updated fallback seed nodes from sipa's DNS seeds
Fix off-by-one errors in use of IsFinalTx()

Previously CreateNewBlock() didn't take into account the fact that
IsFinalTx() without any arguments tests if the transaction is considered
final in the *current* block, when both those functions really needed to
know if the transaction would be final in the *next* block.

Additionally the UI had a similar misunderstanding.

Also adds some basic tests to check that CreateNewBlock() is in fact
mining nLockTime-using transactions correctly.

Thanks to Wladimir J. van der Laan for rebase.
[Qt] harmonize strings used when exporting in addressbookpage
Merge pull request #3579

f3005c8 [Qt] harmonize strings used when exporting in addressbookpage (Philip Kaufmann)
qt: Translation update

Update English .ts file from source as well as pull changes from transifex
to current translation.
Merge pull request #2342

665bdd3 Fix off-by-one errors in use of IsFinalTx() (Peter Todd)
log parameter interactions to debug.log
[Qt] Fix coin control labels update
Move only: extract WriteChainState and UpdatedTip from SetBestChain.
Prepare block connection logic for headers-first.

This changes the block processing logic from "try to atomically switch
to a new block" to a continuous "(dis)connect a block, aiming for the
assumed best chain".

This means the smallest atomic operations on the chainstate become
individual block connections or disconnections, instead of entire
reorganizations. It may mean that we try to reorganize to one block,
fail, and rereorganize again to the old block. This is slower, but
doesn't require unbounded RAM.

It also means that a ConnectBlock which fails may be no longer called
from the ProcessBlock which knows which node sent it. To deal with that,
a mapBlockSource is kept, and invalid blocks cause asynchronous "reject"
messages and banning (if necessary).
build: use -mwindows for gui targets when linking with mingw
use english for all reason strings in IsStandardTx()
Merge pull request #3589 from Diapolo/english-reason

use english for all reason strings in IsStandardTx()
Merge pull request #3591

6986861 build: use -mwindows for gui targets when linking with mingw (Cory Fields)
Add check for valid keys in `importprivkey`

The base58 armoring was checked, but not the resulting private key,
which could be out of range. Fix this by adding a check.
[Qt] fix bitcoin: URI strings (spelling fixes)