Don't cache display rectangle and client rectangle as they can both change during the program lifetime (especially the latter which changes whenever taskbar is moved or shown/hidden) and retrieving them every time they're needed doesn't seem to be a problem performance-wise anyhow. We still cache the list of all the monitors, ideally we'd refresh it when we receive a notification about a display being [dis]connected. Closes #4582. git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@65555 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775