This also moves the event query faking code back to the external
interface and removes the temporary WINED3D_EVENT_QUERY_UNSUPPORTED
return value since wined3d_event_query_create properly fails if no
event query GL extension is supported.

The newly created wined3d_event_query_test will be available for
wined3d-internal use, primarily for synchronizing buffer updates when
using GL_APPLE_flush_buffer_range.

The wined3d_event_query interface will contain most of the functionality:
* Selecting the proper GL extension
* Context handling
* Thread handling

The IWineD3DEventQuery COM interface will use the internal interface
and implement event query faking on top of it (to enable games that
require event queries able to run on drivers that don't implement the
GL extension).