ui: removed 'Save Project' and 'Save Project As' actions

* removed save actions from menu in QtMainWindow
* removed MessageSaveProject and all Listeners
* updated project loading to ask whether old project and db file should be kept at old location
* fixed crash for missing include files
* fixed simple header search within source paths was broken

src/lib/settings/ProjectSettings.cpp

@@ -157,11 +157,6 @@ bool ProjectSettings::setSourceExtensions(const std::vector<std::string> &source
 	return setValues("source/extensions/source_extensions", sourceExtensions);
 }
 
-bool ProjectSettings::isUseSourcePathsForHeaderSearchDefined() const
-{
-	return isValueDefined("source/use_source_paths_for_header_search");
-}
-
 bool ProjectSettings::getUseSourcePathsForHeaderSearch() const
 {
 	return getValue<bool>("source/use_source_paths_for_header_search", false);