Add myself to AUTHORS and CONTRIBUTORS as requested wrt Fix #159.

CONTRIBUTORS

diff --git a/CONTRIBUTORS b/CONTRIBUTORS
index b991c4d..077e55e 100644
--- a/CONTRIBUTORS
+++ b/CONTRIBUTORS
@@ -38,6 +38,7 @@
 Pascal Leroy <phl@google.com>
 Paul Redmond <paul.redmond@gmail.com>
 Pierre Phaneuf <pphaneuf@google.com>
+Radoslav Yovchev <radoslav.tm@gmail.com>
 Shuo Chen <chenshuo@chenshuo.com>
 Yusuke Suzuki <utatane.tea@gmail.com>
 Tobias Ulvgård <tobias.ulvgard@dirac.se>