Fix compile issues with Windows and VMS.

* main.c (initialize_stopchar_map): isblank() is not part of C89.
Install bits for space and tab directly.
* makeint.h: Don't define vfork; autoconf handles this for us.
* vmsjobs.c: Rename NEXT_TOKEN to V_NEXT_TOKEN to avoid conflicts.
* dir.c (print_dir_data_base): Visual Studio C doesn't have int64_t.
* w32/subproc/sub_proc.c (process_begin): Missing arg to memset().
* build_w32.bat: Don't use obsolete Visual Studio flags.
6 files changed