Add more frequently used built-in variables like `Zero`

[Halimao]

Can we add more frequently used built-in variables like

// Zero constant, to make computations faster.
// Zero should never be compared with == or != directly, please use decimal.Equal or decimal.Cmp instead.
var Zero = New(0, 1)

At lease add variables for following

var oneInt = big.NewInt(1)
var twoInt = big.NewInt(2)
var fourInt = big.NewInt(4)
var fiveInt = big.NewInt(5)
var tenInt = big.NewInt(10)
var twentyInt = big.NewInt(20)

// One constant, to make computations faster.
// One should never be compared with == or != directly, please use decimal.Equal or decimal.Cmp instead.
var One = New(1, 0)
// Two constant, to make computations faster.
// Two should never be compared with == or != directly, please use decimal.Equal or decimal.Cmp instead.
var Two = New(2, 0)
......

[SRNissen]

Consider:

[Halimao]

Consider:

I'm sorry, but what does this mean?

[mwoss]

Hi @Halimao. Sure I will consider it :D Personally, I would opt for adding just essential constants, to not overload the API surface with unnecessary ones.

[your-diary]

Possible duplicate of #103.