MSI installer for 64-bit AMD64

MSI installer for 64-bit AMD64

Add support for building 64-bit AMD64 MSI install packages
in addition to 32-bit i386 MSI install packages.

Differences between 32-bit MSI and 64-bit MSI include:
 * no krb4 binaries and libraries
 * no kclient binaries and libraries
 * no krb524 binaries and libraries
 * no leash32.exe
 * new AMD64 UpgradeCode permits parallel installation with 32-bit MSI
 * support for Visual Studio 2005 (VS8, CL1400) merge modules

Open Issues:
 * 32-bit MSI installs kfwlogon.dll on AMD64 systems
 * 32-bit and 64-bit NetIDMgr.exe as startup.  Need to decide
   which should be executed by default.  Only one can run at
   a time.
 * Need to make sure that src/windows/build properly configures
   the site-local.wxi file for Visual Studio 2005 and platform.

ticket: new
component: windows

git-svn-id: svn://anonsvn.mit.edu/krb5/trunk@19922 dc483132-0cff-0310-8789-dd5450dbe970