bigcouch body_too_large error

on urchin:

[Mon, 06 Jan 2014 07:01:47 GMT] [info] [<0.31340.151>] [a271f9f0] undefined - - 'HEAD' /user-847a6ece58ce498e4cd86cb10a6ecaa7 200
[Mon, 06 Jan 2014 07:01:47 GMT] [info] [<0.31340.151>] [a271f9f0] 127.0.0.1 localhost:4096 HEAD /user-847a6ece58ce498e4cd86cb10a6ecaa7 200 ok 10
[Mon, 06 Jan 2014 07:01:47 GMT] [info] [<0.31341.151>] [e6bc2c41] undefined - - 'GET' /user-847a6ece58ce498e4cd86cb10a6ecaa7/u1db_config 200
[Mon, 06 Jan 2014 07:01:47 GMT] [info] [<0.31341.151>] [e6bc2c41] 127.0.0.1 localhost:4096 GET /user-847a6ece58ce498e4cd86cb10a6ecaa7/u1db_config 200 ok 4
[Mon, 06 Jan 2014 07:01:48 GMT] [info] [<0.31378.151>] [aebe65dd] undefined - - 'GET' / 200
[Mon, 06 Jan 2014 07:01:48 GMT] [info] [<0.31378.151>] [aebe65dd] 127.0.0.1 undefined GET / 200 ok 1
[Mon, 06 Jan 2014 07:01:48 GMT] [info] [<0.31379.151>] [206275ad] undefined - - 'GET' / 200
[Mon, 06 Jan 2014 07:01:48 GMT] [info] [<0.31379.151>] [206275ad] 127.0.0.1 undefined GET / 200 ok 1
[Mon, 06 Jan 2014 07:01:48 GMT] [info] [<0.31380.151>] [ccbf9374] undefined - - 'GET' /identities/_design/Identity/_view/pgp_key_by_email/?reduce=false&user_id=%22e929236044f676d81310e
049db7ee40a%22&include_docs=true 200
[Mon, 06 Jan 2014 07:01:48 GMT] [info] [<0.31380.151>] [ccbf9374] 127.0.0.1 localhost:4096 GET /identities/_design/Identity/_view/pgp_key_by_email/?reduce=false&user_id=%22e929236044f6
76d81310e049db7ee40a%22&include_docs=true 200 ok 329
[Mon, 06 Jan 2014 07:01:49 GMT] [info] [<0.31426.151>] [0dfbfa8a] undefined - - 'GET' /user-b53da5ccc53fbd4573b4e14b747c0030/_design%2Fdocs 200
[Mon, 06 Jan 2014 07:01:49 GMT] [info] [<0.31426.151>] [0dfbfa8a] 127.0.0.1 localhost:4096 GET /user-b53da5ccc53fbd4573b4e14b747c0030/_design%2Fdocs 200 ok 9
[Mon, 06 Jan 2014 07:01:49 GMT] [error] [<0.31427.151>] [e5e833bc] Uncaught error in HTTP request: {exit,
                                                                    {body_too_large,
                                                                     content_length}}
[Mon, 06 Jan 2014 07:01:49 GMT] [info] [<0.31427.151>] [e5e833bc] Stacktrace: [{mochiweb_request,stream_body,
                                                5},
                                               {mochiweb_request,recv_body,2},
                                               {chttpd_external,json_req_obj,
                                                3},
                                               {chttpd_show,
                                                send_doc_update_response,6},
                                               {chttpd,handle_request,1},
                                               {mochiweb_http,headers,5},
                                               {proc_lib,init_p_do_apply,3}]
[Mon, 06 Jan 2014 07:01:49 GMT] [info] [<0.31427.151>] [e5e833bc] undefined - - 'PUT' /user-b53da5ccc53fbd4573b4e14b747c0030/_design/docs/_update/put/2568e6cf-a284-45c6-a93a-769b501ef594 500
[Mon, 06 Jan 2014 07:01:49 GMT] [info] [<0.31427.151>] [e5e833bc] 127.0.0.1 localhost:4096 PUT /user-b53da5ccc53fbd4573b4e14b747c0030/_design/docs/_update/put/2568e6cf-a284-45c6-a93a-769b501ef594 500 ok 12

(from redmine: created on 2014-01-06, closed on 2014-01-19, relates #4932 (closed), relates #4961, relates #6187, relates #6444 (closed))