Making pg_hba.conf case-insensitive

I was looking at this TODO item from 2009:

https://www.postgresql.org/message-id/4AA7B197.70002%40usit.uio.no

I have implemented this in the attached patch. It does two things:

o compares words in columns that can only support keywords as
case-insensitive, double-quoted or not

o compares words in columns that can contain user/db names or keywords
as case-sensitive if double-quoted, case-insensitive if not

Here is the 'local' line we install during initdb, and a newly
identically-behaving line:

# TYPE DATABASE USER ADDRESS METHOD
local all all trust
"LOCAL" ALL ALL TRUST

This 9.6 line:

local Test all trust

would have to be represented in PG 10 as:

local "Test" all trust

--
Bruce Momjian <bruce(at)momjian(dot)us> http://momjian.us
EnterpriseDB http://enterprisedb.com

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