* Implemented RSA-2048-PSS + SHA256 signature verification.
* Refactored RSA-2048-OAEP decryption steps to use mbedtls function calls.
* Implemented NCA header main signature verification.
* Replaced Björn Samuelsson's CRC32 algorithm with the hardware accelerated CRC32 checksum calculation from libnx (latest commit with support for calculation in blocks).
* Refactored keydata handling.
* Sealed NCA KAEKs are now generated at startup, and NCA key area entries are now decrypted by keysDecryptNcaKeyAreaEntry(), reducing the number of calls to spl functions.
* The eTicket RSA device key is now retrieved and decrypted at startup. RSA-OAEP wrapped titlekeys are now decrypted by keysDecryptRsaOaepWrappedTitleKey().
* Renamed titlekek -> ticket common key throughout the codebase.
* Added NcaKeyAreaEncryptionKeyIndex_Count and NcaKeyGeneration_Max enum values to nca.h.
* Proper usage of strcasecmp() in some functions.
* Moved syscall hint checks from keys.c to mem.c.
* Define illegal FS characters as an array rather than a char pointer.
* Services are now initialized before the CFW type checks.
* Fixed pcv/clkrst service initialization.
* Implemented additional thread safety and logfile output to service functions.
* Slightly tweaked running service checks.
* Added proper Markdown documentation for the USB ABI.
