ntdll: Add a configure check for the tcdrain function.

Also remove the tcgetattr check that is no longer used.
oleaut32: Add ICreateTypeInfo2::SetVarName implementation.
dplayx: Fix the initial refcount of the IDPLobbySPImpl object.
dplayx: Use consistent naming for the IDirectPlaySP methods.
dplayx: Introduce impl_from_IDirectPlaySP().
dplayx: Simplify ref-counting for IDirectPlaySP.
dplayx: Remove commented out TRACEs that mimic +tid functionality.
dplayx: Remove the unused lock from IDirectPlaySPImpl.
dplayx: Merge the extra struct into IDirectPlaySPImpl.
dplayx: Finish the COM cleanup for IDirectPlaySP.
dplayx: Simplify the creation of an IDirectPlaySPImpl object.
ddraw: Don't imply WINED3DUSAGE_RENDERTARGET on primary surfaces.

If the application actually wants to do 3D rendering on the primary surface,
it should set DDSCAPS_3DDEVICE as well.
wined3d: Enforce WINED3DUSAGE_RENDERTARGET format restrictions on resource creation.
wined3d: Enforce WINED3DUSAGE_DEPTHSTENCIL format restrictions on resource creation.
d3dcompiler: Avoid LPCSTR.
d3dcompiler: Avoid LPCVOID.
ntdll: Avoid TRUE FALSE conditional expressions.
configure: Don't use X_PRE_LIBS.
kernel32/tests: Some tests for initial thread activation context.
ntdll: Inherit default activation context from creation thread.