ITS#9925 Fix some ancient #ifdef checks

Use #elif defined(...) for HAVE_WINSOCK and MACOS. All other instances
of these macros use #ifdef or similar. A compiler may warn about them
not being defined.

In libraries/liblber/sockbuf.c, (DOS && PCNFS) and (DOS && NCSA) were
replaced with HAVE_PCNFS and HAVE_NCSA, respectively. It seems logical
to do the same at the only remaining occurrence of DOS, PCNFS, and NCSA.

Use #if HARDCODE_DATA consistently, replacing two instances of #ifdef.
HARDCODE_DATA is always defined, and this way you can set HARDCODE_DATA
to 0 and have it work, rather than it going down the wrong branch and
failing in these two cases.