New code assist API

This is a re-work of our completion engine. Primary goals are:

- Allow the computation to run in a separate thread so the GUI is not locked.
- Support a model-based approach. QStrings are still needed (filtering, etc), but
internal structures are free to use more efficient representations.
- Unifiy all kinds of *assist* into a more reusable and extensible framework.
- Remove unnecessary dependencies on the text editor so we have more generic
and easily "plugable" components (still things to be resolved).

src/plugins/cpptools/cpptoolsplugin.cpp

@@ -34,13 +34,13 @@
 #include "completionsettingspage.h"
 #include "cppfilesettingspage.h"
 #include "cppclassesfilter.h"
-#include "cppcodecompletion.h"
 #include "cppfunctionsfilter.h"
 #include "cppcurrentdocumentfilter.h"
 #include "cppmodelmanager.h"
 #include "cpptoolsconstants.h"
 #include "cpplocatorfilter.h"
 #include "symbolsfindfilter.h"
+#include "cppcompletionassist.h"
 
 #include <extensionsystem/pluginmanager.h>
 
@@ -113,9 +113,7 @@ bool CppToolsPlugin::initialize(const QStringList &arguments, QString *error)
             m_modelManager, SLOT(updateSourceFiles(QStringList)));
     addAutoReleasedObject(m_modelManager);
 
-    CppCodeCompletion *completion = new CppCodeCompletion(m_modelManager);
-    addAutoReleasedObject(completion);
-
+    addAutoReleasedObject(new CppCompletionAssistProvider);
     addAutoReleasedObject(new CppLocatorFilter(m_modelManager));
     addAutoReleasedObject(new CppClassesFilter(m_modelManager));
     addAutoReleasedObject(new CppFunctionsFilter(m_modelManager));
@@ -141,12 +139,6 @@ bool CppToolsPlugin::initialize(const QStringList &arguments, QString *error)
     mcpptools->addAction(command);
     connect(switchAction, SIGNAL(triggered()), this, SLOT(switchHeaderSource()));
 
-    // Set completion settings and keep them up to date
-    TextEditor::TextEditorSettings *textEditorSettings = TextEditor::TextEditorSettings::instance();
-    completion->setCompletionSettings(textEditorSettings->completionSettings());
-    connect(textEditorSettings, SIGNAL(completionSettingsChanged(TextEditor::CompletionSettings)),
-            completion, SLOT(setCompletionSettings(TextEditor::CompletionSettings)));
-
     return true;
 }