Fixes http://open.silverstripe.org/ticket/6473
When using CSVParser::$columnMapping to map columns to a callback action, it previously used the action name as the key value. This prevented users from defining multiple entries to the same callback. This patch retains those key values and simply runs the callback field name filter later on.
The entire framework repo (with the exception of system-generated files) has been amended to respect the 120c line-length limit. This is in preparation for the enforcement of this rule with PHP_CodeSniffer.
