[krbdev.mit.edu #3415] Windows 64-bit support

[Jeffrey Altman via RT]

A new version of the patch.  This version defines _USE_32BIT_TIME_T in
src\config\win-pre.in for 32-bit platforms.  This removes the need to
always include k5-int.h or win-mac.h at the front of each source file.

This version also defines _CRT_SECURE_NO_DEPRECATE to avoid warning
messages caused by the use of strcpy(), strcat(), etc.