[Docs] Add release notes and bip update for Bip32/HD wallets

doc/bips.md

@@ -9,6 +9,7 @@ BIPs that are implemented by Bitcoin Core (up-to-date up to **v0.12.0**):
 * [`BIP 23`](https://github.com/bitcoin/bips/blob/master/bip-0023.mediawiki): Some extensions to GBT have been implemented since **v0.10.0rc1**, including longpolling and block proposals ([PR #1816](https://github.com/bitcoin/bitcoin/pull/1816)).
 * [`BIP 30`](https://github.com/bitcoin/bips/blob/master/bip-0030.mediawiki): The evaluation rules to forbid creating new transactions with the same txid as previous not-fully-spent transactions were implemented since **v0.6.0**, and the rule took effect on *March 15th 2012* ([PR #915](https://github.com/bitcoin/bitcoin/pull/915)).
 * [`BIP 31`](https://github.com/bitcoin/bips/blob/master/bip-0031.mediawiki): The 'pong' protocol message (and the protocol version bump to 60001) has been implemented since **v0.6.1** ([PR #1081](https://github.com/bitcoin/bitcoin/pull/1081)).
+* [`BIP 32`](https://github.com/bitcoin/bips/blob/master/bip-0032.mediawiki): Hierarchical Deterministic Wallets has been implemented since **v0.13.0** ([PR #8035](https://github.com/bitcoin/bitcoin/pull/8035)).
 * [`BIP 34`](https://github.com/bitcoin/bips/blob/master/bip-0034.mediawiki): The rule that requires blocks to contain their height (number) in the coinbase input, and the introduction of version 2 blocks has been implemented since **v0.7.0**. The rule took effect for version 2 blocks as of *block 224413* (March 5th 2013), and version 1 blocks are no longer allowed since *block 227931* (March 25th 2013) ([PR #1526](https://github.com/bitcoin/bitcoin/pull/1526)).
 * [`BIP 35`](https://github.com/bitcoin/bips/blob/master/bip-0035.mediawiki): The 'mempool' protocol message (and the protocol version bump to 60002) has been implemented since **v0.7.0** ([PR #1641](https://github.com/bitcoin/bitcoin/pull/1641)).
 * [`BIP 37`](https://github.com/bitcoin/bips/blob/master/bip-0037.mediawiki): The bloom filtering for transaction relaying, partial merkle trees for blocks, and the protocol version bump to 70001 (enabling low-bandwidth SPV clients) has been implemented since **v0.8.0** ([PR #1795](https://github.com/bitcoin/bitcoin/pull/1795)).

doc/release-notes.md

@@ -112,6 +112,24 @@ feerate. [BIP 133](https://github.com/bitcoin/bips/blob/master/bip-0133.mediawik
 
 ### Wallet
 
+Hierarchical Deterministic Key Generation
+-----------------------------------------
+Newly created wallets will use hierarchical deterministic key generation
+according to BIP32 (keypath m/0'/0'/k').
+Existing wallets will still use traditional key generation.
+
+Backups of HD wallets, regardless of when they have been created, can
+therefore be used to re-generate all possible private keys, even the
+ones which haven't already been generated during the time of the backup.
+
+HD key generation for new wallets can be disabled by `-usehd=0`. Keep in
+mind that this flag only has affect on newly created wallets.
+You can't disable HD key generation once you have created a HD wallet.
+
+There is no distinction between internal (change) and external keys.
+
+[Pull request](https://github.com/bitcoin/bitcoin/pull/8035/files), [BIP 32](https://github.com/bitcoin/bips/blob/master/bip-0032.mediawiki)
+
 ### GUI
 
 ### Tests