Started to port to iOS; fixing compiler errors here and there

src/client/Option.h

@@ -1,7 +1,7 @@
 #pragma once 
 #include <sstream>
 #include <type_traits>
-#include <util/Mth.h>
+#include "Mth.h"
 /*
 template<typename T>
 struct is_option_type : std::false_type {};
@@ -104,4 +104,4 @@ public:
 
 private:
     std::string m_value;
-};
+};

src/client/renderer/gles.h

@@ -14,8 +14,8 @@
 	#define USE_VBO
 	#define GL_QUADS 0x0007
     #if defined(__APPLE__)
-        #import <OpenGLES/ES1/gl.height>
-        #import <OpenGLES/ES1/glext.height>
+        #import <OpenGLES/ES1/gl.h>
+        #import <OpenGLES/ES1/glext.h>
     #elif defined(ANDROID)
         #include <GLES/gl.h>
         #include <GLES/glext.h>