Update yajl to 1.0.9 and fix the formula.

Add missing `=` in call to `configure`.
Install header files.

Signed-off-by: Adam Vandenberg <flangy@gmail.com>

Formula/yajl.rb

@@ -2,8 +2,8 @@ require 'formula'
 
 class Yajl <Formula
   homepage 'http://lloyd.github.com/yajl/'
-  url 'http://cloud.github.com/downloads/lloyd/yajl/yajl-1.0.8.tar.gz'
-  md5 '26116d41b6466f6b4da7d9e8450f2200'
+  url 'http://cloud.github.com/downloads/lloyd/yajl/yajl-1.0.9.tar.gz'
+  md5 '8643ff2fef762029e51c86882a4d0fc6'
 
   # Configure uses cmake, even though it looks like we're
   # just using autotools below.
@@ -12,7 +12,8 @@ class Yajl <Formula
   def install
     ENV.deparallelize
 
-    system "./configure", "--prefix#{prefix}"
+    system "./configure", "--prefix=#{prefix}"
     system "make install"
+    (include + 'yajl').install Dir['src/api/*.h']
   end
-end
+end