Implement TipWindow in terms of PopupWindow
Fix REPORT_EVENTS in manager.cpp
Close all TipWindow automatically on click
Fix tooltip flicker on ToolBar
Make hot-region bigger for ToolStrip popup
Improve REPORT_EVENTS in manager.cpp to show the Widget type (using typeid)
Report Manager::setMouse() calls if REPORT_EVENTS is defined
Free the right widget in removeChild() (we've to free "child" instead of "this")
Remove unnecessary calls in TipWindow
Fix issue 356: tooltips cause selecting tools require 1 or more extra mouse clicks

This is an old bug in the ui::Manager. We don't need to "free" (release)
the mouse widget when we re-stack windows order (e.g. because the user
clicked the non top-most window).