8.1.5 flaglon(xflag,low,high,flag,mask_count,ii)

flaglon $<$ chanana $<$ BoaChanAna.f90

! NAM: flagaz  (sub)
! DES: set flag where lon>low and <high 
! INP: 
!      low     = lower limit 
!      high    = upper limit
!      xflag   = rank-1 flag array
!      lon_p   taken from data module
! OUT:
!      xflag   = rank-1 flag array
!      mask_count = number of flags changed
!
! HIS: FB040608  adapted from flagtime