Relocate in front of Summoner and other minor updates!

Hey game devs,

This update 1.3.4 comes with a small but useful set of features:

- Custom JS hooks have been added when a Pet appears, retreats, or is knocked out
- Game devs may now call pet.summoner() to get the summoner who has originally summoned this pet
- "Relocating a Pet in front of their Summoner" has been added to the Tips section of this plugin's article (https://aerosys.blog/pet-summon#31-tips)

Fixes:
- It's been fixed that Pets stay inactive in some cases

Don't hesitate to report problems regardless of whether you think it's the plugin's fault or not.

Happy game-making!