Advanced option page: Ensure that value is within the range to avoid problems in case settings were corrupted.
Advanced option page: Set topmost for tooltip window.

This is workaround for
https://connect.microsoft.com/VisualStudio/feedback/details/272350

Fixes #4641
MiniDump: Put dump massage on top.

This was very annoying that this message box end up below MPC-HC window
which obviously couldn't be moved after crash.