Added sample fonts data

extra_fonts/README.txt

@@ -0,0 +1,71 @@
+
+Extra fonts for ImGui.
+THOSE FONTS ARE OPTIONAL.
+
+ImGui embeds a copy of 'proggy_clean' that you can use without any external files.
+Export your own font with bmfont (www.angelcode.com/products/bmfont).
+
+bmfont reads fonts (.ttf, .fon, etc.) and output a .fnt file and a texture file, e.g:
+
+  proggy_clean.fon --> [bmfont] ---> proggy_clean_13.fnt
+                                     proggy_clean_13.png
+
+Configure bmfont:
+
+  - Export .fnt as Binary
+  - Tip: uncheck "Render from TrueType outline" and "Font Smoothing" for best result with non-anti-aliased type fonts. 
+    But you can experiment with other settings if you want anti-aliased fonts.
+
+
+(A) Use font data embedded in ImGui
+
+    // Access embedded font data
+    const void* fnt_data;   // pointer to FNT data
+    unsigned fnt_size;      // size of FNT data
+    const void* png_data;   // pointer to PNG data
+    unsigned int png_size;  // size of PNG data
+    ImGui::GetDefaultFontData(&fnt_data, &fnt_size, &png_data, &png_size);
+
+  1. Load the .FNT data from 'fnt_data' (NB: this is done for you by default if you don't do anything)
+
+    ImGuiIO& io = ImGui::GetIO();
+    io.Font = new ImBitmapFont();
+    io.Font->LoadFromMemory(fnt_data, fnt_size);
+    
+  2. Load the .PNG data from 'png_data' into a texture
+
+
+
+(B) Use fonts from external files
+
+    ImGuiIO& io = ImGui::GetIO();
+
+  1. Load the .FNT data, e.g.
+    
+    // proggy_clean_13 [default]
+	  io.Font->LoadFromFile("proggy_clean_13.fnt");
+	  io.FontTexUvForWhite = ImVec2(0.0f/256.0f,0.0f/128);
+	  io.FontYOffset = +1;
+
+    // proggy_small_12
+	  io.Font = new ImBitmapFont();
+	  io.Font->LoadFromFile("proggy_small_12.fnt");
+	  io.FontTexUvForWhite = ImVec2(84.0f/256.0f,20.0f/64);
+	  io.FontYOffset = +2;
+    
+    // proggy_small_14
+	  io.Font = new ImBitmapFont();
+	  io.Font->LoadFromFile("proggy_small_14.fnt");
+	  io.FontTexUvForWhite = ImVec2(84.0f/256.0f,20.0f/64);
+	  io.FontYOffset = +3;
+	  
+	  // courier_new_16
+	  io.Font->LoadFromFile("courier_new_16.fnt");
+	  io.FontTexUvForWhite = ImVec2(1.0f/256.0f,4.0f/128);
+	  
+	  // courier_new_18
+	  io.Font->LoadFromFile("courier_new_18.fnt");
+	  io.FontTexUvForWhite = ImVec2(4.0f/256.0f,5.0f/256);
+
+  2. Load the matching .PNG data into a texture
+