groonga-httpd: POST メソッドのサポート


現象
----------------

groonga-httpd で、 load コマンドを POST で実行しようとすると 「must send load data as body」という応答だけが帰ってきて読み込みに失敗してしまいます。

例
----------------

```
vagrant@precise64:~/groonga$ curl -v 'http://localhost:10041/d/table_create?name=Abc&key_type=ShortText'
* About to connect() to localhost port 10041 (#0)
*   Trying 127.0.0.1... connected
> GET /d/table_create?name=Abc&key_type=ShortText HTTP/1.1
> User-Agent: curl/7.22.0 (x86_64-pc-linux-gnu) libcurl/7.22.0 OpenSSL/1.0.1 zlib/1.2.3.4 libidn/1.23 librtmp/2.3
> Host: localhost:10041
> Accept: */*
> 
< HTTP/1.1 200 OK
< Server: nginx/1.4.2
< Date: Sun, 18 Aug 2013 08:33:05 GMT
< Content-Type: application/json
< Content-Length: 47
< Connection: keep-alive
< 
* Connection #0 to host localhost left intact
* Closing connection #0
[[0,1376814785.18354,0.00130605697631836],true]
vagrant@precise64:~/groonga$ 
vagrant@precise64:~/groonga$ cat shortdata.txt 
[
[ "_key" ],
[     1 ],
[     2 ],
[     3 ],
[     4 ],
[     5 ],
[     6 ],
[     7 ],
[     8 ],
[     9 ],
[    10 ]
]
vagrant@precise64:~/groonga$ curl -v --data-binary '@shortdata.txt' 'http://localhost:10041/d/load?table=Abc'
* About to connect() to localhost port 10041 (#0)
*   Trying 127.0.0.1... connected
> POST /d/load?table=Abc HTTP/1.1
> User-Agent: curl/7.22.0 (x86_64-pc-linux-gnu) libcurl/7.22.0 OpenSSL/1.0.1 zlib/1.2.3.4 libidn/1.23 librtmp/2.3
> Host: localhost:10041
> Accept: */*
> Content-Length: 125
> Content-Type: application/x-www-form-urlencoded
> 
* upload completely sent off: 125out of 125 bytes
< HTTP/1.1 200 OK
< Server: nginx/1.4.2
< Date: Sun, 18 Aug 2013 08:34:41 GMT
< Content-Type: text/plain
< Content-Length: 27
< Connection: keep-alive
< 
* Excess found in a non pipelined read: excess = 172, size = 27, maxdownload = 27, bytecount = 0
* Connection #0 to host localhost left intact
* Closing connection #0
must send load data as body
vagrant@precise64:~/groonga$ 

```