scp2: remove some very SPECIAL unused macros

Change-Id: I28f2f4bc3c43aac1faf8be35cf7ce89480487102
use SAL_OVERRIDE for WinSalTimer

... and no, we do not "overload" virtual methods.

Change-Id: Iff7c46326974995994e966873ff804092bc53540
vcl: avoid crashes from Timer Queues on shutdown

The timer callback SalTimerProc can be called after DeInitVCL has
deleted the SalInstance, and crash.  Avoid that by calling
WinSalTimer::Stop() and also using the INVALID_HANDLE_VALUE parameter
which waits until the timer callback is done executing.

Change-Id: Ia4cf2cf9dc48904d077e0a691e14107256c50ded
assert that XMLTransformerBase::m_xHandler is initialized

Just seen a test with a null m_xHandler, no idea how that happened.

Change-Id: I2e5ff9d3c799284beea5fdca37fa8a825f8a4756