Restore wpsc_get_visitor_meta filter
Was in previous releases
Removed todo from comment related to meta get filter
restored 3.8.13.3 pre-filters to customer meta
restore 3.8.13.3 filter to allow override of customer id
Merge pull request #1156 from JeffPyeBrook/pr-issue-1149-missing-filter

Restore wpsc_get_visitor_meta filter