Allow pre-configuration of passphrases (-p<passphrase>) to provide enough information for wlantest to be able to derive PMK for each BSS and PTK for each STA going through 4-Way Handshake (at least message 2 and 3 needs to be received).
Whenever a Beacon or Probe Response frame is observed, add or update a BSS entry to maintain current information about the active BSSes.
