Added a new admin config to allow for the selection of custom sort attributes
Refactor Custom sort order config attribute for clarity
Merge pull request #6 from aligent/custom-sort-order

Added a new admin config to allow for the selection of custom sort attributes
Merge remote-tracking branch 'origin/master' into remove-word-if-no-result

Conflicts:
	code/Helper/Data.php
	code/etc/config.xml
	code/etc/system.xml