Picture bugfix, external plugin commands and a couple of checks

Here is a little update on the plugin after the report by Megum on RpgMaker Web. First of all it was fixed the reported bug that would see a weird picture distribution if Screen Resolution and UI Resolution were different (such a the demo project of VisuStella).

Then I checked the leftover issues that were never investigated, such as changing map or scene while the Achievement Pop Up was showing or getting a reward while game was not intialized. Nothing major emerged, more details below!

Finally I added and external command to call the achievement completion (plus I left room to easily add more) in case you might want to call it from a scene or another plugin (the most classic scenario: Achievement Completed on first load of the game). It's most important to note that this external command need to be launched once the game database and plugins are completely loaded, but if you are using a JS script I'm confident you know what you are doing!

VERSION 1.3:

• Fixed pictures misplacements if using a different Screen vs UI resolution
• Investigated the possible issue of teleporting to another map while popping the achievement complete window, no issues have been recorded
• Investigated the possible issue of changing scene (menu, save, game over, title screen) while achievement windows is popping. No fatal error, but it would be better to avoid such simultaneous events or the pop window might be lost
• Investigated the possible issue about giving out rewards while not in the game. The game will IGNORE all the rewards, there is no way to recover them. That said, popping an achievement outside the game need the special external script call to be doable. So shame on you if you pop a rewarding achievement outside the game!
• Added a script call to run the "Complete Achievement" command outside the plugin (see instructions in the description). Be sure to have the database and plugins ready before doing so.