Ticket #291 - cannot use & in a sasl map search filter
Bug Description: The '&' was getting replaced in slapi_re_subs() when processing
search filter mappings.
Fix Description: Created extension of slapi_re_subs() to pass in filter flag.
It checks to see if the '&' is a separator of filter components
or not, by looking for "(&(".
https://fedorahosted.org/389/ticket/291