Autotools: Modernize

* Use pragma once
* Make sure overrides are everywhere
* Clean up code here and there
* Remove useless code from initializer lists

Change-Id: I9c285a803ea36cb32d14b3335757fd4b57f27d02
Reviewed-by: Orgad Shaneh <orgads@gmail.com>

src/plugins/autotoolsprojectmanager/autotoolsbuildconfiguration.h

@@ -25,8 +25,7 @@
 **
 ****************************************************************************/
 
-#ifndef AUTOTOOLSBUILDCONFIGURATION_H
-#define AUTOTOOLSBUILDCONFIGURATION_H
+#pragma once
 
 #include <projectexplorer/buildconfiguration.h>
 
@@ -88,4 +87,3 @@ private:
 
 } // namespace Internal
 } // namespace AutotoolsProjectManager
-#endif // AUTOTOOLSBUILDCONFIGURATION_H