structure: add BCountAVL (a wrapper around BAVL providing a version with BAVL_COUNT defined)
structure: add BCountAVL (a wrapper around BAVL providing a version with BAVL_COUNT defined)

DavidCox1979/badvpn,DavidCox1979/badvpn,DavidCox1979/badvpn,DavidCox1979/badvpn,DavidCox1979/badvpn