Added DestroyWindow to Windows API

This API is supported on all versions of Windows starting with Windows 2000 and is required to generate the WM_DESTORY message for correct window shutdown on those systems.
Removed redundant nothrow
Merge pull request #811 from auroragraphics/master

Added DestroyWindow to Windows API
Add SetWindowPos to Windows API

This API is supported on all versions of Windows starting with Windows 2000 and is required to change window position and size.
Added flags for SetWindowPos
Removed double newline
Merge pull request #812 from auroragraphics/master

Add SetWindowPos and Flags