Modifications for WinCE compatibility

[Corona688]

Re-downloaded the entire CVS to try and compile for WinCE and Win32 with
the newest code...  haven't done Win32 yet, but should have that done
shortly.  Under WinCE, two things:

1) Several instances of snprintf in interface.c and layer3.c.  WinCE
doesn't support snprintf.
2) Again, had to change the declspec code to

#ifdef SDL_SOUND_DLL_EXPORTS
#  define SNDDECLSPEC __declspec(dllexport)
#else
#  define SNDDECLSPEC
#endif

Could the declspec code be put in CVS?  As it was, it was seriously
broken IMO.