Clearify StoreController implementation.

Use bridge pattern to refactor StoreController.
The implementation for different platforms (ios/andorid/editor) can be
seperate clearly.
Clearify StoreInventory implementation.
Clearify StoreInfo implementation.
Fix #if directives for instantiation.
Merge pull request #220 from HolymarsHsieh/BridgePattern

Bridge pattern for platform implementation.
Thanks @HolymarsHsieh