Display renderer information
Turn 1-element array to ref/out param
Prioritize accelerated formats first

Instead of creating a list of all available formats and iterating
through that, we let the driver decide which is the best accelerated
format to use for the user parameters. If no such format exists, we fall
back to generic acceleration or software acceleration, in turn.

This affects issue #21
Fixed DescribePixelFormatPFD

When using the PFD codepath, we now call DescribePixelFormat to retrieve
an exact interpretation of the pixel format selected by the driver.
Improved WGL mode selection

Fixed WGL_ARB_pixel_format attribute selection for doublebuffering,
stereoscopic rendering and hardware acceleration. Implemented
minimization strategy to select the optimal PixelFormatDescriptor in the
fallback path.
Added WGL_DRAW_TO_WINDOW_ARB flag

Without this flag, OpenGL rendering does not work as expected.

Additionally, all WGL_ARB_pixel_format attributes are expected to be
specified in key-value pairs. Fixed double-buffering and stereoscoping
rendering attributes.
Fixed crash in MakeCurrent(null)

MakeCurrent(null) should set the bound device context to zero.
Merge branch 'wgl_issue21'. Fixes issue #21