Implement IAutoComplete to realize input auto completion. CORE-9281, CORE-1419
- The main features of this PR are Auto-Suggest and Auto-Append.
- Auto-Suggest shows a list near the textbox (an EDIT control) when the user has typed partial pathname into the textbox.
- Auto-Append appends complement text into the textbox to complete the pathname with selected status.
- The list of AutoSuggest is a top-level window whose window class is "Auto-Suggest Dropdown". We call it "the drop-down window".
- The drop-down window contains three controls: a listview, a scrollbar and a sizebox.
- The drop-down window watches the input into the textbox. If the textbox changed, then the window updates the list.
- The sizebox control enables the user to resize the drop-down window.
