Fixed the ant build for cpp98 so that the new SBE_HAS_CMATH #define could be used during sbe build.  Simply do: "ant -Dcpp.has.cmath cpp", and the build should work.

Fixed the ant build for cpp98 so that the new SBE_HAS_CMATH #define could be used during sbe build.  Simply do: "ant -Dcpp.has.cmath cpp", and the build should work.