CMake: Semi-automatic cleanups

* Shorten header guards
* Use override and auto where possible
* Remove useless destructors, etc.
* Remove private slots sections, unify private: sections
* Use member initialization where it makes sense

Change-Id: I00eaf6d706adc16859176d1b68c631d3336bb39f
Reviewed-by: Tim Jenssen <tim.jenssen@theqtcompany.com>

src/plugins/cmakeprojectmanager/cmakefilecompletionassist.cpp

@@ -54,9 +54,6 @@ using namespace ProjectExplorer;
 CMakeFileCompletionAssistProvider::CMakeFileCompletionAssistProvider()
 {}
 
-CMakeFileCompletionAssistProvider::~CMakeFileCompletionAssistProvider()
-{}
-
 bool CMakeFileCompletionAssistProvider::supportsEditor(Core::Id editorId) const
 {
     return editorId == CMakeProjectManager::Constants::CMAKE_EDITOR_ID;