Werror: Enable warnings as errors

Added C/CXX warning messages similar to MRAA (w/ -Werror).

    * Added syslog warning for missing switch cases
    * Cleaned up uint vs int usage
    * Fixed redifinition errors for C structs
    * Added virtual destructors for base classes
    * Removed redundant CMAKE_CXX_FLAGS from COMPILE_FLAGS for all three
      wrapper languages.  The CMAKE_CXX_FLAGS were showing up twice in
      the compile commands for the wrappers.
    * Added CMake WERROR option to enable/disable warnings as errors for
      all targets.
    * Disable a handful of compiler warnings for the wrapper cxx files,
      this minimizes the number of warnings from auto-generated code).

Signed-off-by: Noel Eck <noel.eck@intel.com>

src/ili9341/ili9341_gfx.hpp

@@ -45,6 +45,11 @@ namespace upm
              * @param h Screen height
              */
             GFX(int16_t w, int16_t h);
+
+            /**
+             * Empyt virtual destructor
+             */
+            virtual ~GFX() {};
              
             /**
              * Sends a pixel color (RGB) to the driver chip. This must be
@@ -403,4 +408,4 @@ namespace upm
             bool _cp437;
             static const unsigned char font[];
     };
-}     
+}