Make use of basegfx rect clipper in wmf import. Greatly speeds
up reading WMFs with lots of clip actions. Fixes n#535304, applies
patches/dev300/svtools-wmf-clipperf.diff

A fix for n#411855, to make preview object refresh in all cases.
Applied patch svtools-update-ole.diff

 * cppcanvas/source/mtfrenderer/implrenderer.cxx: fixed round
   corners rectangle drawing (basegfx tools use portion of width and
   height to specify the corners width and height)

Thanks to Joseph Powers for reporting this.

In practice the changeset is 'inspired' by vosremoval-mutex.diff
but was essentially redone manually

LocalGuard is a wrapper guard around the SolarMutex.
SolarMutexGuard already provide this function.

Factorized the Guarded piece of code to locate the TopWindow under a
given Point, which was repeated verbatim in 4 different functions
That allowed as a bonus to remove the need for a ClearableGuard, and
allow the use of a straight SolarMutexGuard.

Few place in the code use vos::OClearbleGuard aGuard(Application::GetSolarMutex());
or something similar.
This new class hide this ugliness into
SolarMutexClearableGuard aGuard;

This also has the merit to push down the vos:: dependency down into one location
for this kind of access, which will simplify the vos dependency removal.

Most user of OGuard, use it to guard the SolarMutex.
using something like
vos::OGuard aGuard(Application::GetSolarMutex())

Which will now be written
vcl::SolarMutexGuard aGuard;

This will also, as a side effect remove the use of vos::Guard in many
sources, simplifying the migration out of ::vos