Summary of changes:

- filter -> SQL translation bugfixes
- several memory leaks fixups
- improved configurability:
    - allows definition of  uppercasing function to support CIS matching on databases that do
    case sensitive compares (this fixes up Oracle issues, example updated)
    - allows more flexibility in stored procedures interface (different parameter order, optional return
      codes - see samples, and comments in backsql.h)
- synchronize function interfaces to recent changes in prototypes ("const" clauses etc.) made for all backends
  (those changes led to compile-time errors)