Add support for disabling Pets in certain worlds. Adds #49
Some spelling changes
Save Pets on creation through Pet Selector
Method refactor
Improve support for disabling messages in the language file
Huge changes and improvements to the Pet Data system

This commit reworks the Pet Data mechanics, improving the overall
performance and efficiency. This fixes the saving of data to files and
SQL databases, avoiding duplicate and inconsistent results when loading
Pets. It also fixes certain issues regarding Horse Data not loading
correctly (Fixes #40).