6/10 Update: General Improvements

A small list of general improvements, which should enhance the gameplay and look.

*  Chapter 4 is now dark, with the character holding a lantern to see.

*  Changed the battle scenes to *mostly* match the terrain.

*  Changed the music for the Seal Guardian (I especially like this music).

*  Changed the music for cave battles to the regular battle music (the old music is now just for the mini bosses, as intended).

*  Fixed the Inn/Shop/Hospital/Library music so they cover the entire area they're supposed to.

*  Fixed a random battle probability error in the Goblin Lair in Chapter 4.

*  Changed Leather Shield to Wooden Shield and gave it a sprite.