Add letter spacing support for svg

[AvaelKross]

This adds a support for letter spacing in exported svg files. Also I fixed the parser to set charSpacing according to letter-spacing css rule. I have no time to make sure test works, so please feel free to improve it. I tested it manually for iText, and it works like a charm and keeps positioning very accurately.

[asturur]

i did not even know letter-spacing was a SVG thing.

I have to check the SVG export, but looks good overall

[asturur]

this Canvas text can be actually be exported like this in the SVG

how your changes will influence the Itext export? can you post some simple screenshot?

[AvaelKross]

hmm.. this is a sample itext object on canvas:

and this is an svg version:

(ignore sizing etc., these were just differently cropped)

[asturur]

i guess the itext code needs to be cleared from the actual charspacing code and left your one

[asturur]

i think this has been solved with latest master. Anyway since the new text changes, the svg ouput must be handled differently

[asturur]

@AvaelKross more than one year passed, but @brentcappello made me notice today that here there was some unmerged work. So i cleaned it up and merge it.