* tik: check for common certificate availability before attempting to convert a personalized ticket to a common one. The raw common certificate chain data for the ticket signature issuer is now returned.
* usb: skip waitMulti call in the USB background thread if an invalid endpoint max packet size was received from the USB host in the previous while loop iteration.
* Codestyle fixes.
* NCA contexts for NCAs with titlekey crypto will now be generated even if the ticket can't be retrieved, in order to be able to use ncaReadContentFile() with them.
* Moved aes128XtsNintendoCrypt() out of nca.c.
* Updated disclaimer in all source files.
* Improved signed payload (certificate, ticket) handling.
* Prefer strlen + strcmp over strncmp whenever possible.
* Simplify header file inclusions in source files.
* Simplify background gamecard thread logic.
* Properly close keys file handle if there's a key parse error.
* Update NcaKeyGeneration enum.
* Small changes to save.c/h.
Will probably have to revert some USB changes...
