[PATCH] Add inline comments to the pg_hba_file_rules view

Hi,

This patch proposes the column "comment" to the pg_hba_file_rules view. 
It basically parses the inline comment (if any) of a valid pg_hba.conf 
entry and displays it in the new column.

For such pg_hba entries ...

host db jim 127.0.0.1/32 md5 # foo
host db jim 127.0.0.1/32 md5 #bar
host db jim 127.0.0.1/32 md5 #     #foo#

... it returns the following pg_hba_file_rules records:

postgres=#  SELECT type, database, user_name, address, comment
  FROM pg_hba_file_rules
  WHERE user_name[1]='jim';

  type | database | user_name |  address  | comment
------+----------+-----------+-----------+---------
  host | {db}     | {jim}     | 127.0.0.1 | foo
  host | {db}     | {jim}     | 127.0.0.1 | bar
  host | {db}     | {jim}     | 127.0.0.1 | #foo#
(3 rows)


This feature can come in quite handy when we need to read important 
comments from the hba entries without having access to the pg_hba.conf 
file directly.

The patch slightly changes the test 004_file_inclusion.pl to accommodate 
the new column and the hba comments.

Discussion: 
https://www.postgresql.org/message-id/flat/3fec6550-93b0-b542-b203-b0054aaee83b%40uni-muenster.de

Best regards,
Jim