Fixed compilation and linkage on Win with MSVS2013 and WinSDK8.1
Add WIN81_SDK_DIR config variable
Use PrismaticMath::round() instead of round().
Minor changes in UpdatesProcessor.{h,c}pp
Merge pull request #1 from dreamer-dead/msvs2013_win81

MSVS2013&WinSDK8.1