Added cache support for large icons in udImages

Refactore code to delete item's cache icon
Added methods to make&remove Backup&Cache folder

Added cache support for large icon (save and load from sqlite db) in
ulDatabase
Fix bug about VirtualTree's OnExpanding event

Now some vstList's methods can to share with other VirtualTree
Added code to populate vstMRU and vstMFU

vstRecents and vstMostUsed uses large icons and uses some vstList's
events
Now in GraphicMenu's virtualtrees, it need only one click to expand or
to run items