fix compile errors on Linux

On Linux, <sys/time.h> must be included to make struct timeval known.
string.h must be included to use memset().
A jump to a label (done_close_file) must not cross local declarations. The corresponding code has been encapsulated in a block.
The use of the STRINGIZE macro leads to an error where the compiler sees the #version 430 sequence as an invalid preprocessor directive.
Move add_subdirectory(lib/glfw) before examples compile in CmakeList.txt to avoid build dependence error.
Reference:
	jhannemann openglredbook#3
	elmindreda openglredbook#5

Author: robotchaoX

CMakeLists.txt

@@ -20,6 +20,8 @@ set (CMAKE_DEBUG_POSTFIX "_d")
 
 find_package(OpenGL REQUIRED)
 
+add_subdirectory(lib/glfw)
+
 if(WIN32)
 set(COMMON_LIBS vermilion ${OPENGL_LIBRARIES} optimized glfw3 debug glfw3_d)
 elseif (UNIX)
@@ -101,7 +103,5 @@ ENDIF (${CMAKE_SYSTEM_NAME} MATCHES "Linux")
 include_directories( include )
 include_directories(lib/glfw/include)
 
-add_subdirectory(lib/glfw)
-
 ADD_CUSTOM_TARGET(debug ${CMAKE_COMMAND} -DCMAKE_BUILD_TYPE:STRING=Debug ${PROJECT_SOURCE_DIR})
 ADD_CUSTOM_TARGET(release ${CMAKE_COMMAND} -DCMAKE_BUILD_TYPE:STRING=Release ${PROJECT_SOURCE_DIR})

include/vapp.h

@@ -2,6 +2,9 @@
 #define __VAPP_H__
 
 #include "vgl.h"
+#ifndef _WIN32
+#include <sys/time.h>
+#endif
 
 class VermilionApplication
 {

lib/vbm.cpp

@@ -4,6 +4,7 @@
 #include "vgl.h"
 
 #include <stdio.h>
+#include <string.h>
 
 VBObject::VBObject(void)
     : m_vao(0),

lib/vdds.cpp

@@ -603,6 +603,7 @@ void vglLoadDDS(const char* filename, vglImageData* image)
     if (image->target == GL_NONE)
         goto done_close_file;
 
+{
     size_t current_pos = ftell(f);
     size_t file_size;
     fseek(f, 0, SEEK_END);
@@ -641,6 +642,7 @@ void vglLoadDDS(const char* filename, vglImageData* image)
         height >>= 1;
         depth >>= 1;
     }
+}
 
 done_close_file:
     fclose(f);

src/10-fur/10-fur.cpp

@@ -13,6 +13,7 @@
 
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 
 BEGIN_APP_DECLARATION(FurApplication)
     // Override functions from base class

src/11-doublewrite/11-doublewrite.cpp

@@ -14,6 +14,7 @@
 #include "LoadShaders.h"
 
 #include <stdio.h>
+#include <string.h>
 #include <string>
 
 #define MAX_FRAMEBUFFER_WIDTH 2048

src/11-oit/11-oit.cpp

@@ -14,6 +14,7 @@
 #include "LoadShaders.h"
 
 #include <stdio.h>
+#include <string.h>
 #include <string>
 
 #define MAX_FRAMEBUFFER_WIDTH 2048

src/11-overdrawcount/11-overdrawcount.cpp

@@ -14,6 +14,7 @@
 #include "LoadShaders.h"
 
 #include <stdio.h>
+#include <string.h>
 #include <string>
 
 #define MAX_FRAMEBUFFER_WIDTH 2048

src/12-particlesimulator/12-particlesimulator.cpp

@@ -110,7 +110,7 @@ void ComputeParticleSimulator::Initialize(const char * title)
     compute_prog = glCreateProgram();
 
     static const char compute_shader_source[] =
-        STRINGIZE(
+        STRINGIZE( \
 #version 430 core\n
 
 layout (std140, binding = 0) uniform attractor_block