Bugs/issues found in March 2nd test

[FelicitusNeko]

• [x] Items may occasionally get lost
  • Seems to be when an item is received between a save and a Game Over
  • May have something to do with how checks are currently stored
• [x] Boss rooms are broken (bosses being fought in PSI Key Pedestal rooms)
• [x] Skipping to Cursed Seal should set current_boss to 2
• [x] Test what happens if Cursed Seal is received while in Entrance
• [x] Clarify item recieve text
• [x] Indicate how many purchases were made on each cache
• [x] Tweak cache price!!!
  • This is also mentioned in #1
• [x] More Compass tiles?
  • Not sure if this'll get done; I've already broken the map gen code as it is

[FelicitusNeko]

Idea to replace "more compass tiles": Portable Compass artifact maybe?

[FelicitusNeko]

Receiving the Cursed Seal in a fresh new game while in the Entrance makes the game lock up for an extended period of time. Assuming that it's taking too long to cull/curse the monster population. This generally shouldn't happen anyway, since the Cursed Seal is in a fixed location in the game, but the game assumes at least 75% of the monster population has been defeated by the time the Cursed Seal can be picked up, which apparently can lead to performance hits if that's not the case.