Remove unit plugin.
Add README with info about move unity plugin.
Merge remote-tracking branch 'upstream/master' into remove_unity_plugin

Conflicts:
	unity_plugin/.gitignore
	unity_plugin/src/org/onepf/openiab/UnityPlugin.java
	unity_plugin/src/org/onepf/openiab/UnityProxyActivity.java
	unity_plugin/unity_src/Assets/OpenIAB-demo/OpenIABTest.cs
	unity_plugin/unity_src/Assets/Plugins/OpenIAB/Android/OpenIAB_Android.cs
	unity_plugin/unity_src/Assets/Plugins/OpenIAB/IOpenIAB.cs
	unity_plugin/unity_src/Assets/Plugins/OpenIAB/Inventory.cs
	unity_plugin/unity_src/Assets/Plugins/OpenIAB/JSON.cs
	unity_plugin/unity_src/Assets/Plugins/OpenIAB/OpenIAB.cs
	unity_plugin/unity_src/Assets/Plugins/OpenIAB/OpenIABEventManager.cs
	unity_plugin/unity_src/Assets/Plugins/OpenIAB/Options.cs
	unity_plugin/unity_src/Assets/Plugins/OpenIAB/OptionsVerifyMode.cs
	unity_plugin/unity_src/Assets/Plugins/OpenIAB/Purchase.cs
	unity_plugin/unity_src/Assets/Plugins/OpenIAB/SkuDetails.cs
	unity_plugin/unity_src/Assets/Plugins/OpenIAB/WP8/OpenIAB_WP8.cs
	unity_plugin/unity_src/Assets/Plugins/OpenIAB/iOS/OpenIAB_iOS.cs
	unity_plugin/unity_src/Assets/Plugins/iOS/AppStoreBridge.mm
	unity_plugin/unity_src/Assets/Plugins/iOS/AppStoreDelegate.h
	unity_plugin/unity_src/Assets/Plugins/iOS/AppStoreDelegate.mm
	unity_plugin/unity_src/Assets/Plugins/iOS/AppStoreDelegate.mm.meta
	unity_plugin/unity_src/unity_src.userprefs
Merge pull request #273 from kirich1409/remove_unity_plugin

Remove unit plugin.