Make value box size parametrized

[yorl1n]

Now the width of value box is defined as follows:
let tw = context.measureText(options.valueText ? text : ('-' + padValue(0, options))).width;

So the width is defined according to initial value length.

F.e. I don't need leading zeroes and decimals (000.00)-> I specify component as follows:

valueDec: 0,                                     
valueInt: 1,

Initial value is 0, the width of the value box is appropriate. Now I load value 1000 and it looks ugly.
So I propose to move out dimensional config of the value box and make it configurable in px and % (from the total dimensions).

[Mikhus]

It makes sense, thank you. So I will keep the current behavior as default one and if there would be width specified it will be applied then.
This is scheduled for the next release 2.0.8.

[yorl1n]

Thanks!

[Mikhus]

Implemented in release 2.0.8, published.