- FDB: filter

I have implemented FDBSetFilter() in the xBase driver. It is basically 
just a set of C structs which are given to FDBSetFilter() so FDB does 
not actually parse any filter expressions - just inerprets the C 
structs. I have put a little hard-coded test in ifdb. I guess ifdb is 
going to have to be able to parse out, at least, simple "SET FILTER TO" 
commands so I will look into that.

I plan to add a call-back for filtering as well. This can be used to 
bypass the above method.

Finally; I picked up a copy of Base III+ on eBay so it should be here 
within the week. Then I can work on the dBase III+ indexs (NDX).

Peter