Removed useless Alert Box

For some reason URLs got changed again...
So I've added slider, that lets You choose between them - to avoid making Updates, just to change them

+ "Safety Indicator" - shows when a Video is NSFW or contains Spoilers
- Useless piece of Code

Updated URLs (Fix for Audio Player and possibly Video Player in the Future)
Updated "Additional OPs and EDs" to work as intended

* Made the Script independent of the Extension
+ Audio Mode
+ Link to the Videos Source

! Please, report any Bugs You encounter

So... Today I realized that AnimeThemes slightly changed their API - after a few months(?), the Script is finally working again!!

Manually Added Arifureta S2 Songs (Hard-Coded - missing in the DataBase)

Fixed:
1) Issue causing some Songs to trigger Alert Box

Added:
+ Additional Openings and Endings

Fixed issue with Zoku Owarimonogatari Opening triggering Alert Box

Bug Fix + Instruction how to check whether Song is missing, or is it a Script Bug

Bug Fix - when there was only an Endings Section, Video Player didn't appear

Changed DataBase, so now there are more Entries - the Process might take a while longer, so avoid instant clicking

Small Change to avoid confusion when Song is Missing