[krbdev.mit.edu #8662] Windows build is broken

[Sergey Ilinykh via RT]

Just tried to use your windows/README to build it with vs2015 x64.
It compiled a lot of stuff but failed with

Making in
        cl  -DWINSOCK -DWIN32 -DWINDOWS -D_AFXDLL -DNO_KRB4 -DNO_STATUS_BAR
-DUSE_MESSAGE_BOX -DDBG -DNO_AFS -I..\.. -I..\..\include
-I..\..\windows\include -I.\..\..\include -I.\..\..\include\krb5
-I..\..\windows\include -DWSHELPER=1 -DKRB5_DNS_LOOKUP=1
-DWIN32_LEAN_AND_MEAN -DKRB5_DEPRECATED=1 -DKRB5_PRIVATE
-D_CRT_SECURE_NO_DEPRECATE -DUSE_LEASH=1 -DDEBUG -D_CRTDBG_MAP_ALLOC  /Od
/Zi /MDd -nologo /EHsc /W3 -Fdobj\AMD64\dbg\\ -FD  -Foobj\AMD64\dbg\\ -c ...
Krb4EditDomainRealmList.cpp
c:\src\krb5\src\windows\leash\stdafx.h(16): fatal error C1083: Cannot open
include file: 'afxwin.h': No such file or directory
NMAKE : fatal error U1077: '"C:\Program Files (x86)\Microsoft Visual Studio
14.0\VC\BIN\amd64\cl.EXE"' : return code '0x2'

apparently there is no such file anywhere when mfc component is not
installed, but there is nothing in the README about mfc. README has to be
updated. Ideally makefiles should check if mfc is availabl and only then
compile dependent subprojects.

Best Regards,
Sergey