MRLE Extension - Save/Load file picker

This is an extension for the Multiplatform Runtime Level Editor (MRLE). To compile it requires the main MRLE package (v1.31 or higher)!
Use this extension to allow your users to save and load multiple level files. It contains a popup that allows you to enter a new file name or to pick a level from existing files.
Installation:
- import this package and the default demo (LE_ExampleEditor) will automatically show the file selection on level save or load.
- simply use LE_ExtensionInterface.Load or LE_ExtensionInterface.Save properties to trigger the popup from your code. Examples using the LE_ExtensionInterface are in the ExampleGame_Editor class.
- contains example script for uploading MRLE levels to Steam Workshop (requires Steam Workshop - ESI!).
This extension does not work in the Unity Web Player, because file access from the browser is not permitted.