pywsgi: ignore errors that happen when socket is closed (for example if it was  already closed by websocket handler)

--HG--
extra : transplant_source : %1DS%BBz%9B%D1%02%0B%99%CC%DF%CDZ%96%C6%EF%C9gV%AD

pywsgi: do not use chunked transfer encoding in case of 304 and 204 responses as it creates a non-empty message body which is against RFC and causes some browsers to fail. Based on the patch by Nicholas Piël.

--HG--
extra : transplant_source : %E1Cx%D2%B7%87%0F%B3dW%DF%05%C8SF%23E%09u%01

Note, that zero-length string encoded with chunked transfer-encoding is a non-empty message-body.
That causes some browsers to fail (e.g. safara and firefox on macos)

Thanks to Nicholas Piël.

--HG--
extra : transplant_source : %1B%B56%81%1F%87%BA%E9%ADdeE%7EAIm%F0%DDoz

--HG--
extra : transplant_source : s%1B%C7Wk%82%8C%DC%CE%FE%CC6%197%1FZC8%D9%99

--HG--
extra : transplant_source : %9CRz%85%94%E8%D8n%1D%CBu%1F%14%89r%5B%DB4P%E4

this makes subclassing the handler easier

--HG--
extra : transplant_source : %27%CC%A3%89%16%AE%22i%E6%0F%88%EA%025%01%81%27%C0Rz

--HG--
extra : transplant_source : %ED%01_%E4-Z%FC5%0C%89%AA%E8%B9%8A%FD%28%C47%81L

--HG--
extra : transplant_source : I%1C%28%11%94c%AAW%E5R%5B%B1%D4W%89%A4%ECC%A1%EE

--HG--
extra : transplant_source : -%CArs%BEj%18%A4%1A%0C%8F%AC%CE%E0%D9%8C%A4j%8E%A5

--HG--
extra : transplant_source : Q9%011%FE%ACdS%D6%14%F7%C7%98%82%CB%09%3B%3F%90%D5

--HG--
extra : transplant_source : %91%1F%03%84v%7E%20%B5%A3l%E8%02%06%FBIB%DD%8A.%D4

--HG--
extra : transplant_source : %C8%82%26%AE%B3%95%F5%27%8D%FCxu%40%E7V%E1m%B3%40%DA

--HG--
extra : transplant_source : %E0%91%0F9%AAI%F0%10%C2%17%86%81%F1O%8C%0A%01%C3%1C%BD

--HG--
extra : transplant_source : %60%BEmj%FB8%A8zW%B8%CA%1E%DD%99A%A1%1Cs%14I

--HG--
extra : transplant_source : %7BJ%5C%DC%1B%B2%87%07%D6io%CD%E1y%9Eyurm%A2

--HG--
extra : transplant_source : %BF1%93%5C%1Ck%7F%9DA%E8%09%CD%2A9%EB%D8%5C%7B8%B1

--HG--
extra : transplant_source : %B45%80%3F%83%91%E3%10-%D9%D0%9B%2A%9F%98%D5%82lc%B0

--HG--
extra : transplant_source : %D7%08%1F%3B%B8%E3%DBX%C9d%C9b%D9j%0F%89D%27%E9%F2

--HG--
extra : transplant_source : %E5%90q%E6%02%7B%D8%91%ED%97%89%AC0%A6D%C8d%E5%08%40

--HG--
extra : transplant_source : %CB%BD%CE%83t%F7%02c%BB%B1%01%C5%AF%BD%09l%13K%A1%C1

--HG--
extra : transplant_source : %02N%7C%F8%F4%AFH%13%C7%AC%16%10%CE%16%3C%80%3C%1B%0D%C9

--HG--
extra : transplant_source : D%99l00%7E%5D%EEBG%BB%2CSF%12%CE%8B%01PK

--HG--
extra : transplant_source : %A2c%7CPD%F0%DC%2C9R6%10Ez%9E%0D%C7%D8%CB%DC

--HG--
extra : transplant_source : %EA%F3%98n%11i%F9Fa%3C%93%E5%B8T%FE%03%26%A6%D8U

--HG--
extra : transplant_source : %5B%7C7%9B%D1%D3%07%06D%C6v%7D%3A%DBG%84%26%22%CC%3E

--HG--
extra : transplant_source : r%FE%C3%C3%B7%BC%927%11%1Fh%D1%85%9F%91s6%29T%DE

--HG--
extra : transplant_source : %B4%7BT%D7I%A8%16%7E%E8z%1A%F5%28mm%19%0Dp%26%BA

--HG--
extra : transplant_source : %02%FF%A1Yr%EB%B7t%0C%BA%DC%E8d%E6%3C%26R%F4%15o

--HG--
extra : transplant_source : %A0%DB%8C%FB%C0%F5%2C%7D%18%9D%1D%DB%BB2%7D%0B%D6%1B%13%DE

--HG--
extra : transplant_source : %21%13%27%3E%FF%E4%91%AD%84%1BG%F9%9C%D4%0D%B9B%B4Q%FC

--HG--
extra : transplant_source : Zj%D2%01pC%C0%88%C7%E6%266%BEJ%AF%86%18%B6%97L

--HG--
extra : transplant_source : %26%FCzQ%D6u%B3C%82%E9%00%E7%DF%95%03D%0C%0C%00%3C

--HG--
extra : transplant_source : %88h%A9%F2P%EC%CB%D0%D5%1A%A1h%E8%F1%7C%AE%818dT

--HG--
extra : transplant_source : BH_%F4%C4%DC%9C%8D%8B%DC%86%BB%2B%40%87r%CF%FD%B6%22

--HG--
extra : transplant_source : e3%FB%7F%86%0F%F5y/%C5%18%AC%EE%98%5C.%2A%F5%FC%A0

--HG--
extra : transplant_source : .%EE%D7y%C3%F6%23%9D%A9/%D3%16%83%97u%E1%D7%00%92Y

--HG--
extra : transplant_source : %00%D8%AA%0D%F2%3D%DD%14%C9%C7%1B%CB%1C%ED%09%07%8C%BF%DF%06

--HG--
extra : transplant_source : %8Fm%00l%DE%40%09%974E%7E%A0%1F%23%3F%FF%81%F0%D1%80

--HG--
extra : transplant_source : %F43%1E%A6mh%01%A4%0Fs%CB%8D5%FF%16i%C1%40%0B%BD