fix user roles, timestamps; code simplifications for custom fields

Bug Fix No 1) user roles were not consistent (manage_wpsc_support_tickets / manage_wpsct_support_tickets)
Bug Fix No 2) time stamps for staff replies were wrong (time(), current_time() is not the same timezone) 
Code simplification 1) states, countries & text fields to be managed via array
Code simplification 2) user roles as array