rename vars for clarity and correctness
rename vars for clarity and correctness

first_high_bit_idx -> local_first_high_bit_idx
"local_first_high_bit_idx > 0" -> clearly_done
max_ignored -> min_low_bits_ignored (it was always the minimum
    number of bits that this function would allow to be ignored,
    not the maximum.  Mayhap it had been named "max" just because
    the expression that generates it contains std::max?)

idupree/Lasercake,Lasercake/Lasercake,Lasercake/Lasercake,Lasercake/Lasercake,Lasercake/Lasercake,elidupree/Lasercake,elidupree/Lasercake,idupree/Lasercake,elidupree/Lasercake,idupree/Lasercake,idupree/Lasercake,elidupree/Lasercake,idupree/Lasercake,idupree/Lasercake,elidupree/Lasercake,elidupree/Lasercake,elidupree/Lasercake,Lasercake/Lasercake,idupree/Lasercake