Patch v0.99.12

[list] [*] Fixed a bug where the abandoned mine could not be clicked. [*] Resolved an issue where empty save files were incorrectly displayed as deleted. [*] Fixed a bug where summoned caravans would disappear after loading a save file. [*] Fixed an issue in the map editor where invalid saves were allowed. [*] Fixed a bug in Level 4-3 where the monster wave in June was incorrect. [*] Resolved an issue where monster spawn points were abnormal after loading a save file. [/list]