updated h2xs

updated h2xs

Changes:
a) Docs and examples for -x updated;
b) Path to xxxx.h would not be changed to /usr/include/xxxx.h
unless this file exists (outside of VMS, I'm afraid to make an error
there). - Useful with -x option, when the file may be eaten via -I
inside -F.
c) .h file would be scanned only if needed.
d) typemap would be generated (with T_PTROBJ).
e) Documentation (=list) for autogenerated guys would be
included into POD.
f) duplicated XSUBs would not be generated;
g) arguments to XSUBs being arrays are recognized (note that
xsubpp would probably choke on such guys).

-x option requires C-Scan-0.3 (releases a couple of minutes ago to
    ftp://ftp.math.ohio-state.edu/pub/users/ilya/perl
should propagate to CPAN soon).