Merge pull request #9 from kazeburo/master

buffering a first chunk
refactor around buffering chunk
Checking in changes prior to tagging of version 0.09.

Changelog diff is:

diff --git a/Changes b/Changes
index 0e1b1be..d596346 100644
--- a/Changes
+++ b/Changes
@@ -1,5 +1,9 @@
 Revision history for Perl extension Plack::Middleware::Deflater

+
+0.09  Mon May 24 14:24:04 JST 2013
+        - buffering a first chunk. It contains only the gzip header
+
 0.08  Mon Jun 18 23:40:04 JST 2012
         - do compress->close instead of autoflush to write gzip footer
test deflate
use Compress::Zlib directory for performance