Better configuring for Windows build

[SAM-tak]

Summary of changes

• Add "FindWindowsSDK" module

• If found WindowsSDK, use it to DXSDK path

• Add CMake Variable for support XInput

• Add OIS_ prefix to all option variable of CMake

Affected backeds

• CMake
• Windows
• DirectInput
• XInput

[SAM-tak]

sorry i forgot branch with new name...