Fix build failures caused by new C runtime library
- isnan, snprintf, struct timespec are now defined, attempt to
redefine them leads
- P_tmpdir, tzname are no more defined
-  lfind() and lsearch() in lf_hash.c had to be renamed,  declaration
conflicts with some C runtime functions with the same name declared in
a header included by stdlib.h

 Also fix couple of annoying warnings :
- remove #define NOMINMAX from config.h to avoid "redefined" compiler
warnings(NOMINMAX is already in compile flags)

- disable incremental linker in Debug as well (feature not used much
and compiler crashes often)


Also simplify package building with Wix, require Wix 3.9 or later
(VS2015 is not compatible with old Wix 3.5/3.6)