Change squid_log to just match the access log format

[tstack]

The other message pattern should be a separate format. Other changes:

• Set multiline to false so config checking will complain about lines that do not match.
• Change the mime_type pattern to capture the rest of the line since it's the easiest way to get the whole type without missing anything.
• Accept more than just the GET method and change the existing 'method' capture to be 'hier'.
• Add 'ipaddress' collation for the client and source IP addresses.
• Set 'foreign-key' to true for the response_code so that it is not graphed in the SQL view.