[tex-live] laulatex quiting: fix your writable cache path

[Akira Kakuto]

Hi Peter,

> In that case ptexlib.h could contain
>   #if defined(__linux__) && defined(_FEATURES_H)
>   #error ptexlib.h must be included first
>   #endif
> plus something analogous for MSVC.

Mingw seems to include _mingw.h always, so __MINGW_H is defined
after an inclusion of a header.
Visual Studio includes crtdefs.h in many standard headers, where
_INC_CRTDEFS is defined. However there are many other headers which don't
include crtdefs.h. For example, sys/types.h, in which the type off_t
is defined, does not include crtdefs.h. I cannot find a complete
method in Visual Studio to check if a standard header is included.
But I think it may not be needed to be complete, because the problem
is mainly related to off_t:

#if defined(_WIN32) && (defined(_INC_CRTDEFS) || defined(_OFF_T_DEFINED) || defined(__MINGW_H))
  #error ptexlib.h must be included first.
#endif


Best regards,
Akira KAKUTO