* Instead of iterating through the folder every time you change the search query by one letter, iterate through the "coredirmenu" (the game's interpretation of the folder) instead. MUCH, much less likely to lag to fuck and back.
* Hide a bit of complexity in filesrch.c instead of having the entire thing exposed to mess with. For example, closefilemenu() instead of manually freeing the struct each time.
* Refactor some stuff.