Improper variable sanitization
Fixes #2166 calling newreply with no tid does not show the correct error page
Fixes #2167 Calling polls.php with invalid pid shows sql error instead of correct error page
Fixes #1702 canonlyviewownthreads Permission Bug
Fixes #2059 Post Tools won't show up until a Thread Tool exists
Fixes #1515 Attachement in first post lost after merging posts below
Fixes #1611 '&' in RSS feed titles
Fixes #2134 AdmincP Bug
Fixes #2125 Admin CP Viewing Warning wrong link
Fixes #1871 Mod CP user search Post Count column alignment
Fixes #1927 User merge - Source account avatar left on server
Fixes #2182 Apostrophe in DB password causes PHP error
Adds format_time_duration() function
Added setting for CSS minification.

Added a new setting (off by default) to server & optimisation to
enable/disable CSS minification.
Write minified CSS to new .min.css file.
Load .min.css file if minify is enabled.
Updating variable names as per @nmalcolm's
Again updating variable name.
Fixes #1443 View thread notes - PgSQL
Fixes #2019 function affected_rows in db_pgsql.php calls pg_affected_rows with the wrong parameter