wined3d: Fixed potential reference of freed backBuffer array in IWineD3DDeviceImpl_SetFrontBackBuffers.

advapi32: Add support for using the Mac Keychain services as a backend for the credential functions instead of the registry.

Add stubs for these so that the tests link.

ole32: Clean up properly in ClientRpcChannelBuffer_SendReceive in the case where PostMessageW fails.

ole32: Store the dispatch parameters in the message state structure to allow them to be initialised earlier in the sequence of IRpcChannelBuffer calls.

wined3d: Rewrite condition in vshader_program_add_param() to actually distinguish between two cases.

Adjust type of loop variable in INT21_Ioctl_Char().

user32: Fix variable type in SCROLL_HandleScrollEvent().  Remove useless check in SCROLL_SetScrollInfo().