Changes for V2.8.6:
 - reset the default number of bootstraps for the CPD method
   to 1 in controlfiles/standard/cpd.txt
 - added documentation for the "UseL2Fluxes" options switch
   to the L3 control file in controlfiles/templates/L3.txt
 - implemented the "UseL2Fluxes" switch in qcls.py;
   - if switch is present and set to "Yes" then fluxes (ustar,
     Fh, Fe and Fc) will be expected in the L2 file and will
     not be calculated from the covariances in the L2 file
   - if the switch is absent or set to "No" then fluxes will
     be calculated from the covariances in the L2 file