cmake/win: add windows SDK and target definitions

we need a windows Vista SDK and want to target Windows XP SP2
cmake: add specific MFC stuff and clean up target definitions
repair stuff I broke in the past
cmake/util_bootloader: clean up
desura_browserhost,toolhelper,utilhelper: add WIN32 flag
[not done] managers: fix singleton mutex on win32
bootloader_win: fix path and names of libs
uicore: fix theme loading problems on win32
serivce_win: fixed for win32
service_win: fix dll loading on win32
serive_win: check cert only on official build
some more win32 stuff
util/os: add getMcfCachePath() and use it
fixup
cmake: don't install Unix tools on Win32