msvc-inval: Allow three invalid parameter handling modes.

msvc-inval: Allow three invalid parameter handling modes.

* lib/msvc-inval.h: Don't include <stdlib.h> here.
(DEFAULT_HANDLING, HAIRY_LIBRARY_HANDLING, SANE_LIBRARY_HANDLING): New
macros.
(gl_msvc_inval_ensure_handler, TRY_MSVC_INVAL, CATCH_MSVC_INVAL,
DONE_MSVC_INVAL): Implement DEFAULT_HANDLING. Treat
SANE_LIBRARY_HANDLING as a no-op.
* lib/msvc-inval.c: Treat SANE_LIBRARY_HANDLING as a no-op. Include
<stdlib.h>.
(gl_msvc_invalid_parameter_handler): Implement DEFAULT_HANDLING.