Support all text stroke options

[dpashkevich]

Support all text rendering modes via the stroke parameter. (Spec)
Examples:

doc.text(35, 25, "Octonyan loves jsPDF", {
    stroke: 0 // Fill text
});

doc.text(35, 25, "Octonyan loves jsPDF", {
    stroke: 1 // Stroke text
});

doc.text(35, 25, "Octonyan loves jsPDF", {
    stroke: 2 // Fill, then stroke text
});


doc.text(35, 25, "Octonyan loves jsPDF", {
    stroke: 3 // Neither fill nor stroke text (invisible). 
});

[MrRio]

It'd be good if we could pass names into this

{ stroke: 'fill' }

[Uzlopak]

@MrRio
Close this please, as it is modified by PR #1401

[Uzlopak]

Will be part of #1433