Add a "constants" file for housing metavariables that are constant.

Such metavariables include the implemented RESOURCE_DIRECTORY and
related things.
Use the "constants" for the resource directory paths.

This plus File.join is more cross-compatible.
Double quote supremacy.

Double quotes are better.
Some slightly-more-professional function names and such.
Some whitespace tweaks.
Some slightly-more-professional variable names and parentheses.
Merge branch 'master' of github.com:wlcsc-acsl/kittehvpenguin

Conflicts:
	health.rb
	kittehvpenguin.rb
	player.rb

Conflicts appear to be resolved.

Signed-off-by: Kristofer Rye <kristofer.rye@gmail.com>