doc: Document the real key for the sorting dirs before files toggle

Documentation said 'o', but the implementation said 't'. I chuckled when
reading my own code:

  case INPT_CHAR('t'): // o - toggle sorting dirs before files
ADC: Support CIDs with lengths between 128 and 512 bits

This removes the assumption that all CIDs are tiger hashes.
cc.c: Don't throttle users who are granted a slot