todo:
    
    nca: functions for fs section lookup? (could just let the user choose...)
    nca: function to write re-encrypted nca headers / nca fs headers (don't forget nca0 please)
    nca: function to patch the private npdm acid signature from a program nca + patch the acid signature from the nca header
    
    tik: make sure the common crypto cert (XS20, XS22) is available when fakesigning a ticket
    tik: automatically dump tickets to the SD card?
    tik: use dumped tickets when the original ones can't be found in the ES savefile?
    
    gamecard: hfs0 filelist generation functions
    
    pfs0: filelist generation functions
    pfs0: full header aligned to 0x20 (nsp)
    
    romfs: filelist generation functions
    
    bktr: filelist generation functions (wrappers for romfs filelist generation functions)
    
    title: more functions for title lookup (filters, patches / aoc, etc.)
    title: more functions for content lookup (based on id?)