P2Pool release 13.0 - HARDFORK, UPGRADE REQUIRED

[Forrest Voight]

P2Pool release 13.0 - HARDFORK, UPGRADE REQUIRED - commit hash:
f3a0e8dfcd872716123771db7900cdcd963b91ce

Windows binary: http://u.forre.st/u/xqerwrpk/p2pool_win32_13.0.zip
Windows binary signature: http://u.forre.st/u/viejmrru/p2pool_win32_13.0.zip.sig
Source zipball: https://github.com/forrestv/p2pool/zipball/13.0
Source tarball: https://github.com/forrestv/p2pool/tarball/13.0

After 50% of each P2Pool's mining power has upgraded, warnings will be
displayed to everyone who hasn't upgraded. Approximately 24 hours
after 95% of the mining power has upgraded, the switch will happen.

Changes:
* Hardfork at 95% upgraded:
** Bitcoin share period increased from 10 to 30 seconds to cater to
ASIC miners. Avalon/BFL/ASICMINER devices should start working well
after this.
** Litecoin share period increased from 10 to 15 seconds
** Litecoin payouts spread over 3 block-lengths instead of 12,
reducing dust payouts
** Transaction pre-forwarding greatly simplified, allowing future
network traffic reductions
** Maximum share difficulty multiplier increased from 10x to 30x to
give more freedom to below share difficulty adjustments
** OP_RETURN used in last txout to prevent UTXO database spam
** Stratum nonce length increased from 4 to 8 bytes, allowing for
future Avalon support without having to use the "avalon" branch

* Automatically increase share difficulty to prevent payouts below
"dust threshold", 0.001 BTC and 0.03 LTC
* Automatically increase share difficulty to prevent any single node
from making more than 5% of shares, by default
* Worker username parameters (+PSEUDOSHARE_DIFF/SHARE_DIFF) not longer
have to be in a specific order
* Support for submitblock RPC call in new Litecoin versions
* Fixed incompatibility with ASICMINER BE Blade
* Updated bootstrap address list