doc: Add historical release notes

Add all known release notes for versions since 0.3.12,
thanks to Matt Corallo for collecting them on the wiki.

doc/release-notes/release-notes-0.4.0.md

@@ -0,0 +1,70 @@
+Bitcoin version 0.4.0 is now available for download at:
+http://sourceforge.net/projects/bitcoin/files/Bitcoin/bitcoin-0.4.0/
+
+The main feature in this release is wallet private key encryption;
+you can set a passphrase that must be entered before sending coins.
+See below for more information; if you decide to encrypt your wallet,
+WRITE DOWN YOUR PASSPHRASE AND PUT IT IN A SECURE LOCATION. If you
+forget or lose your wallet passphrase, you lose your bitcoins.
+Previous versions of bitcoin are unable to read encrypted wallets,
+and will crash on startup if the wallet is encrypted.
+
+Also note: bitcoin version 0.4 uses a newer version of Berkeley DB
+(bdb version 4.8) than previous versions (bdb 4.7). If you upgrade
+to version 0.4 and then revert back to an earlier version of bitcoin
+the it may be unable to start because bdb 4.7 cannot read bdb 4.8
+"log" files.
+
+
+Notable bug fixes from version 0.3.24:
+
+Fix several bitcoin-becomes-unresponsive bugs due to multithreading
+deadlocks.
+
+Optimize database writes for large (lots of inputs) transactions
+(fixes a potential denial-of-service attack)
+
+
+Wallet Encryption
+
+Bitcoin supports native wallet encryption so that people who steal your
+wallet file don't automatically get access to all of your Bitcoins.
+In order to enable this feature, choose "Encrypt Wallet" from the
+Options menu.  You will be prompted to enter a passphrase, which
+will be used as the key to encrypt your wallet and will be needed
+every time you wish to send Bitcoins.  If you lose this passphrase,
+you will lose access to spend all of the bitcoins in your wallet,
+no one, not even the Bitcoin developers can recover your Bitcoins.
+This means you are responsible for your own security, store your
+passphrase in a secure location and do not forget it.
+
+Remember that the encryption built into bitcoin only encrypts the
+actual keys which are required to send your bitcoins, not the full
+wallet.  This means that someone who steals your wallet file will
+be able to see all the addresses which belong to you, as well as the
+relevant transactions, you are only protected from someone spending
+your coins.
+
+It is recommended that you backup your wallet file before you
+encrypt your wallet.  To do this, close the Bitcoin client and
+copy the wallet.dat file from ~/.bitcoin/ on Linux, /Users/(user
+name)/Application Support/Bitcoin/ on Mac OSX, and %APPDATA%/Bitcoin/
+on Windows (that is /Users/(user name)/AppData/Roaming/Bitcoin on
+Windows Vista and 7 and /Documents and Settings/(user name)/Application
+Data/Bitcoin on Windows XP).  Once you have copied that file to a
+safe location, reopen the Bitcoin client and Encrypt your wallet.
+If everything goes fine, delete the backup and enjoy your encrypted
+wallet.  Note that once you encrypt your wallet, you will never be
+able to go back to a version of the Bitcoin client older than 0.4.
+
+Keep in mind that you are always responsible for your own security.
+All it takes is a slightly more advanced wallet-stealing trojan which
+installs a keylogger to steal your wallet passphrase as you enter it
+in addition to your wallet file and you have lost all your Bitcoins.
+Wallet encryption cannot keep you safe if you do not practice
+good security, such as running up-to-date antivirus software, only
+entering your wallet passphrase in the Bitcoin client and using the
+same passphrase only as your wallet passphrase.
+
+See the doc/README file in the bitcoin source for technical details
+of wallet encryption.