[xml] Compiling 2.3.7

[Peter Jacobi <pj walter-graphtek com>]

Dear Daniel, All,

Compiling 2.3.7 (after using 2.2.x for a long time) on WIN32 using the
WATCOM compiler was a (almost) painless pleasure so far.

Observations:

** There are still some minor warnings when using character
classification Macros, which are designed for UTF16, on 8bit characters.

** In the process of using libxml.h to clean up the prolog of the
sources, the 
"#define INCLUDE_WINSOCK" in nanohttp.c and nanoftp.c were lost. I did
introduce 
this #define to avoid pulling in winsock for all the sources. Any
objection to reintroducing this approach?

** For a quick hack to enable timing in xmllint for WIN32, I suggest:
void gettimeofday (struct timeval *tv, void *p) {
    FILETIME ft;
    unsigned long microseconds;
    GetSystemTimeAsFileTime (&ft);
    microseconds = ft.dwLowDateTime / 10;
    tv->tv_usec = microseconds % 1000000;
    tv->tv_sec = microseconds / 1000000;
}
What's the second parameter, anyway?

** Is there a use case for continuing program execution, when xmlMalloc
fails?
Otherwise I would suggest to move checking for 0 return, generating an
error message and exiting into xmlmemory.h.

Regards,
Peter Jacobi