code style fixes:

- reordered includes to prevent accidental dependencies.
- moved arch specific files into their own folder (easier to include with cmake).
- renamed non-class files to reflect new code style (lower case with underscores).
- using full relative paths for includes (easier for understanding dependencies).
- using #pragma once instead of classic-style header guards.

src/lib/arch/IArchSystem.h

@@ -16,11 +16,10 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef IARCHSYSTEM_H
-#define IARCHSYSTEM_H
+#pragma once
 
-#include "IInterface.h"
-#include "stdstring.h"
+#include "common/IInterface.h"
+#include "common/stdstring.h"
 
 //! Interface for architecture dependent system queries
 /*!
@@ -58,5 +57,3 @@ public:
 	virtual void setting(const std::string& valueName, const std::string& valueString) const = 0;
 	//@}
 };
-
-#endif