Document http_exception, drop all mentions of SystemRoute
Document http_exception, drop all mentions of SystemRoute

KeepSafe/aiohttp,esaezgil/aiohttp,juliatem/aiohttp,arthurdarcet/aiohttp,moden-py/aiohttp,arthurdarcet/aiohttp,arthurdarcet/aiohttp,panda73111/aiohttp,panda73111/aiohttp,mind1master/aiohttp,z2v/aiohttp,panda73111/aiohttp,singulared/aiohttp,mind1master/aiohttp,Eyepea/aiohttp,z2v/aiohttp,pfreixes/aiohttp,rutsky/aiohttp,juliatem/aiohttp,singulared/aiohttp,moden-py/aiohttp,alex-eri/aiohttp-1,elastic-coders/aiohttp,mind1master/aiohttp,playpauseandstop/aiohttp,AraHaanOrg/aiohttp,jashandeep-sohi/aiohttp,moden-py/aiohttp,jashandeep-sohi/aiohttp,hellysmile/aiohttp,elastic-coders/aiohttp,esaezgil/aiohttp,z2v/aiohttp,AraHaanOrg/aiohttp,alex-eri/aiohttp-1,alex-eri/aiohttp-1,vaskalas/aiohttp,esaezgil/aiohttp,jettify/aiohttp,KeepSafe/aiohttp,rutsky/aiohttp,KeepSafe/aiohttp,jettify/aiohttp,rutsky/aiohttp,vaskalas/aiohttp,hellysmile/aiohttp,jashandeep-sohi/aiohttp,pfreixes/aiohttp,singulared/aiohttp,jettify/aiohttp,vaskalas/aiohttp,elastic-coders/aiohttp