Add three features
(1) optimize by gperf
(2) improve memory allocation for speedup
(3) remove memory leaks during Compiler::Lexer::tokenize
change return value type from ref of ArrayRef to simple ArrayRef
modify PERL_DIR path of gen/test_generator.pl
Checking in changes prior to tagging of version 0.13.

Changelog diff is:

diff --git a/Changes b/Changes
index d9e693a..83f228c 100644
--- a/Changes
+++ b/Changes
@@ -1,5 +1,11 @@
 Revision history for Compiler-Lexer

+0.13 : Tue Jun 25 16:30:00 2013
+     - changed type of return value from reference of array reference to simple array reference
+     - optimized by gperf
+     - improved memory allocation for speedup
+     - removed memory leaks during tokenize
+
 0.12 : Mon May 27 16:40:00 2013
      - added META.yml and optimized annotation methods