Adds version.json, removes version.txt

Author: James Chen

version.json

@@ -0,0 +1,10 @@
+{
+    "prebuilt_libs_version":"v3-deps-1",
+    "freetype":"2.5.0",
+    "curl":"7.26.0",
+    "jpeg":"9.0",
+    "png":"1.6.2",
+    "tiff":"4.0.3",
+    "webp":"0.2.1",
+    "websockets":"v1.23-chrome32-firefox24"
+}