admin - product manager filtering

The filters are in place and, more or less, working. Management
categories aren't supported in elastic yet.
product manager - fixed # of results now supported
admin - product editor

bug fix in variations for variation id of '00'.
bug fix in flexeditor for images.
bug fix in flexedit tab of new product editor (images script had
incorrect context)
admin - customer editor bug fix

zero is no longer a valid CID.