*Create an IStorage interface and Storage abstract class to use instead of Stream

* Improve AES-XTS performance by ~16x

* Double AES-CTR performance: 800 MB/s -> 1600 MB/s on a 6700K

* Add AES-XTS tests

* Add AES benchmark and AES-CTR writing

* Add support for a hashed FAT in save files

* Add option to export decrypted NCA

* Allow opening decrypted package1 and package2

* Make sure romfs disposal can cascade all the way down

* Validate NCA, NPDM and package2 signatures