Link correct VS2015 C libraries for debug builds

When building with VS2015 and NODEBUG is not set, link with the
debugging versions of ucrt.lib and vcruntime.lib.  Based on work by
Chris Kingsley.

https://github.com/krb5/krb5/commit/e92dde11a96c23fd68df846260203de4cd09efb4
Author: Greg Hudson <ghudson@mit.edu>
Commit: e92dde11a96c23fd68df846260203de4cd09efb4
Branch: master
 src/lib/Makefile.in              |    4 ++++
 src/windows/kfwlogon/Makefile.in |    4 ++++
 2 files changed, 8 insertions(+), 0 deletions(-)