doc: update release-notes and bips.md for BIP111

Also includes a09db7c [trivial] Minor format fixes

doc/bips.md

@@ -0,0 +1,4 @@
+BIPs that are implemented by Zcash (up-to-date up to **v1.1.0**):
+
+* Numerous historic BIPs were present in **v1.0.0** at launch; see [the protocol spec](https://github.com/zcash/zips/blob/master/protocol/protocol.pdf) for details.
+* [`BIP 111`](https://github.com/bitcoin/bips/blob/master/bip-0111.mediawiki): `NODE_BLOOM` service bit added, but only enforced for peer versions `>=170004` as of **v1.1.0** ([PR #2814](https://github.com/zcash/zcash/pull/2814)).

doc/release-notes.md

@@ -20,3 +20,20 @@ inputs each. Starting from this release, `-mempooltxinputlimit` will be enforced
 before the Overwinter activation height is reached, but will be ignored once
 Overwinter activates. The option will be removed entirely in a future release
 after Overwinter has activated.
+
+`NODE_BLOOM` service bit
+------------------------
+
+Support for the `NODE_BLOOM` service bit, as described in [BIP
+111](https://github.com/bitcoin/bips/blob/master/bip-0111.mediawiki), has been
+added to the P2P protocol code.
+
+BIP 111 defines a service bit to allow peers to advertise that they support
+bloom filters (such as used by SPV clients) explicitly. It also bumps the protocol
+version to allow peers to identify old nodes which allow bloom filtering of the
+connection despite lacking the new service bit.
+
+In this version, it is only enforced for peers that send protocol versions
+`>=170004`. For the next major version it is planned that this restriction will be
+removed. It is recommended to update SPV clients to check for the `NODE_BLOOM`
+service bit for nodes that report versions newer than 170004.