add floating point comparison functions

[icasimpan]

## https://stackoverflow.com/questions/8654051/how-can-i-compare-two-floating-point-numbers-in-bash
##
num1_gt_num2() {
    local num1=$1
    local num2=$2

    local retval=$FALSE
    if (( $(echo "$num1 > $num2" | bc -l) )); then
        retval=$TRUE
    fi

    echo $retval
}

num1_lt_num2() {
    local num1=$1
    local num2=$2

    local retval=$FALSE
    [[ "$(num1_gt_num2 $num1 $num2)" = "0" ]] && retval=$TRUE

    echo $retval
}```