The pg_service.conf parsing thread [0] made me realize that we have a hardwired
line length of max 256 bytes. Lifting this would be in line with recent work
for ecpg, pg_regress and pg_hba (784b1ba1a2 and 8f8154a50). The attached moves
pg_service.conf to use the new pg_get_line_append API and a StringInfo to lift
the restriction. Any reason not to do that while we're lifting other such limits?
cheers ./daniel