Fix typo in function call name
Fix return value in utility function to return custom keys
Fix incorrect variable name in get custom values utility function
more translation implementation
Split load checkout data into two functions, wpsc_checkout_form_fields and wpsc_checkout_unique_names
New functions ruturn arrays of values
Pass each meta key through a validation function
Implemented visitor meta meta key alias function.
IMplemented visitor meta key database upgrade function.
completed visitor meta key alias function implementation
added check to prevent internal meta keys from being aliased
Merge pull request #909 from JeffPyeBrook/pr-visitor-meta

PR Visitor Meta Bug Fix + Visitor Meta Value Alias + Visitor Meta Database Upgrade