Only "lwip/arch.h" is expected to include "arch/cc.h". This is the same
spirit than "lwip/opt.h" for "lwipopts.h" and "lwip/sys.h" for
"arch/sys_arch.h".
- The abstraction from crypto framework was not well suitable to MBEDTLS, so I decided to move everything into an own file.
- I removed several #defines and created function prototypes instead - this is more type-safe, and users don't need to reinvent the function signatures.
- Header files were splitted into a public and a private part.
- Only SNMPv3 authentication was tested, privacy not yet.