Remove local glfw3 lib for osx. (+1 squashed commit)

Squashed commits:
[34cc3b7] Adds osx example. (+6 squashed commits)
Squashed commits:
[20330f2] Uses glfw by brew install.
[0427861] Renames imguiex folder name to imguiex-ios
[f9e27e5] Renames ios_example to apple_example.
[44f8fe3] Updates the glfw header/library path.
[919f279] Renames target from imguiex to imguiex-ios since there is already a imguiex-osx target now.
[24395f5] Adds osx example.

examples/apple_example/imguiex-osx/Assets.xcassets/AppIcon.appiconset/Contents.json

@@ -0,0 +1,64 @@
+{
+  "images" : [
+    {
+      "idiom" : "mac",
+      "size" : "16x16",
+      "scale" : "1x"
+    },
+    {
+      "idiom" : "mac",
+      "size" : "16x16",
+      "scale" : "2x"
+    },
+    {
+      "idiom" : "mac",
+      "size" : "32x32",
+      "scale" : "1x"
+    },
+    {
+      "idiom" : "mac",
+      "size" : "32x32",
+      "scale" : "2x"
+    },
+    {
+      "idiom" : "mac",
+      "size" : "128x128",
+      "scale" : "1x"
+    },
+    {
+      "idiom" : "mac",
+      "size" : "128x128",
+      "scale" : "2x"
+    },
+    {
+      "idiom" : "mac",
+      "size" : "256x256",
+      "scale" : "1x"
+    },
+    {
+      "idiom" : "mac",
+      "size" : "256x256",
+      "scale" : "2x"
+    },
+    {
+      "idiom" : "mac",
+      "size" : "512x512",
+      "scale" : "1x"
+    },
+    {
+      "size" : "512x512",
+      "idiom" : "mac",
+      "filename" : "icon_imgui_180x180.png",
+      "scale" : "2x"
+    },
+    {
+      "idiom" : "mac",
+      "size" : "512x512",
+      "scale" : "2x"
+    }
+  ],
+  "info" : {
+    "version" : 1,
+    "author" : "xcode"
+  }
+}

examples/apple_example/imguiex-osx/Assets.xcassets/Contents.json

@@ -0,0 +1,6 @@
+{
+  "info" : {
+    "version" : 1,
+    "author" : "xcode"
+  }
+}