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-0.3.14.md

@@ -0,0 +1,11 @@
+Version 0.3.14 is now available
+http://sourceforge.net/projects/bitcoin/files/Bitcoin/bitcoin-0.3.14/
+
+Changes:
+* Key pool feature for safer wallet backup
+Gavin Andresen:
+* TEST network mode with switch -testnet
+* Option to use SSL for JSON-RPC connections on unix/osx
+* validateaddress RPC command
+eurekafag:
+* Russian translation