Update BuildWindows for 64 only

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Not sure why I have these conflicts as I've merged master. In any case this still doesn't successfully build because during the rake build section it can't find qtmake:

-- Found Qt4: C:/Qt/4.8.6/bin/qmake.exe (found version "4.8.6")
CMake Error at cmake/modules/FindQt4.cmake:1265 (MESSAGE):
  Qt qmake not found!
Call Stack (most recent call first):
  CMakeLists.txt:19 (FIND_PACKAGE)

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Opened #162 instead