TextEditor: Make automatic completion timeout configurable

Allow to configure the timeout in the range from 0 to 500ms.

Task-number: QTCREATORBUG-13393
Change-Id: I3e421109db919ab0dd5d63b8cbb9339fce132dbb
Reviewed-by: Leena Miettinen <riitta-leena.miettinen@theqtcompany.com>
Reviewed-by: Erik Verbruggen <erik.verbruggen@theqtcompany.com>

src/plugins/texteditor/codeassist/codeassistant.h

@@ -40,6 +40,7 @@
 namespace TextEditor {
 
 class CodeAssistantPrivate;
+class CompletionSettings;
 class IAssistProvider;
 class TextEditorWidget;
 
@@ -52,6 +53,7 @@ public:
     ~CodeAssistant();
 
     void configure(TextEditorWidget *editorWidget);
+    void updateFromCompletionSettings(const TextEditor::CompletionSettings &settings);
 
     void process();
     void notifyChange();