Combat, Player, and UI updates

- Got rid of the in game menu window. Instead, using the text area
under the game window for text output and buttons/menus on the right
side for actions.
- Added a bit more to the combat system. Enemies fight back now (attack
only, so far).
- Finalized random encounter chances. Chance of encounter now dependent
on terrain type.
- Set up enemy zones for future use.
- Added combat initiative. Adds chance for enemies to strike first.
- Fixed player’s ability to run from a monster. Player is no longer
guaranteed to run.
- Added basic level up text.
- Removed some debugging text.
- Altered player stat functions.
- Added player spells based on level.
- Set HP and MP boundaries for player. Can’t go below 0 or above max
limits.
- Started adding spells and effects.