Start of 0.11E

[Tom Harding]

As a start towards XT version 0.11E, I merged some good work done by contributors.  The hope is that these changes will be more likely to get tested together as part of the master branch.  As a small project of all volunteers, we don't have the luxury of waiting for multiple tested ACKs on every change.

Review of the larger changes like #109 (Thin blocks) and #90 (Deterministic mempool limiting) are very welcome.

This is not a release, just a merge advisory.  No binaries are being distributed. 


Bitcoin XT differs from other recent forks in a few ways.  It

• Branches from Core as of 0.11.0, which was released on July 12, 2015.  Other forks are tending to branch much later.
• Implements BIP101.  Just as with CLTV, if another size fork implementation (or other consensus change) gains enough support, XT will adopt it.
• Contains other features which are not contained in any other fork. The website could use some updating updating to reflect XT's unique traffic-shaping support!

Bitcoin XT is an alternative node implementation which makes some basic choices differently than bitcoin core.  The most important ones are:

• Respect for the usefulness of unconfirmed transactions. No RBF.
• Respect for lightweight (SPV) wallets.  XT aims to be the best option for serving SPV clients.  Support for connection bloom filtering is not optional.