Avoid duplicate StillRender() calls after interactive render.

When LOD was enabled and user interacted with the scene, we ended up with 2
calls to StillRender(). That was because the logic in
vtkPVGenericRenderWindowInteractor was redundantly calling StillRender(). Fixed
that.

Change-Id: Ib0ebafcb17d59e50bc5335de8a6b9c3cbed5563f
Merge topic 'fix_double_still_renders' into next

c36f973 Avoid duplicate StillRender() calls after interactive render.
BUG #14320: Turn on user-prompts on error on Windows.

In general turn off error prompts. This is where the process waits for
user-input on any error/warning. In past, we turned on prompts on Windows.
However, for client processes, we capture the error messages in the UI and
for the server-processes, prompts can cause unnecessary interruptions. Hence
we turn off prompts all together.

Change-Id: Idc8b27485ab1d6a7b70580a38d9b4d7340688e0d
Merge topic '14320_disable_user_prompts' into next

0e41f20 BUG #14320: Turn on user-prompts on error on Windows.