Added support for windows in sc_benchmark.cc

- Replaced __WIN32 with __WIN32__.
- Fixed location of SCL_BASE_EXPORT macro.
- Added support to get memory usage and time usage on windows.
Added SCL_SCHEMA_EXPORT macro for entities in fedex-plus generated code.
(Fixes linker errors for some tests on MSVC)
Merge pull request #218 from stepcode/review/msvc_fixes

Review/msvc fixes
fix link errors on Windows.