Implement health and mana for player and enemies meters with functional meters

[vjodar]

Not yet decided if exact numbers should be shown beside the meter, as it could take too much space. Either way, player should be able to get a feeling of how many hits they can take before dying at a glance. They should also be able to get this information about the enemy they're fighting.

Health and mana will start at a lower value and increase as better gear if crafted and equipped.

Also need to implement some tweening whenever player or enemy takes damage or when the player restores health or mana.

[vjodar]

As of commit #89: "Implemented functioning health and mana meters", the player has a functioning health and mana system which is shown by the Meters portion of the HUD. It is very basic right now, with no animations or tweening, nor does it have numbers beside it as I think I don't want it after all.

Health and mana don't start small and increase as better gear is equipped either because currently, I feel it would be too bizarre to see the health and mana meters go up and down as gear if crafted (you need to remove/give up your current armor piece in order to upgrade it). So instead, better gear will simply provide some damage reduction.

Still have yet to implement a health system for the enemies.

[vjodar]

As of commit #90: "Health and mana meters now tween", meters now increase or decrease smoothly over time. Might need to tweak the rate at which they tween later (or perhaps make rate itself increase or decrease based on the magnitude of health/mana loss/gain), but for now I'm good with it.

[vjodar]

As of commit #93: "Enemies now have functional healthbars", enemies now have health meters that are more simple than the player's, but are still tweened smoothly.