Update release notes

Author: petertodd

release-notes.md

@@ -4,6 +4,9 @@ python-bitcoinlib release notes
 v0.5.0
 ======
 
+Major fix: Fixed OpenSSL related crashes on OSX and Arch Linux. Big thanks to
+everyone who helped fix this!
+
 Breaking API changes:
 
 * Proxy no longer has ``__getattr__`` to support arbitrary methods. Use
@@ -13,6 +16,13 @@ Breaking API changes:
 New features:
 
 * New RPC calls: getbestblockhash, getblockcount, getmininginfo
+* Signing and verification of Bitcoin Core compatible messages. (w/ pubkey recovery)
+* Tox tests
+* Sphinx docs
+
+Notable bugfixes:
+
+* getinfo() now works where disablewallet=1
 
 v0.4.0
 ======