consider adding a default font path variable

[mateusvahl]

Hi,
I usually save my fonts into a single folder("./src/fonts"), I think many people do also.
We could add a variable for font path, when is defined, the path is prefixed to the font-scr of ks-font-face mixin.

example:

ks-font-src = './myfolder/fonts/'
font-face( "Roboto", "Roboto-Regular-webfont", normal )

@font-face {
  font-family: "Roboto";
  font-weight: normal;
  src: url("./myfolder/fonts/Roboto-Regular-webfont.eot");
  src: url("./myfolder/fonts/Roboto-Regular-webfont.eot?#iefix") format("embedded-opentype"), url("./myfolder/fonts/Roboto-Regular-webfont.woff2") format("woff2"), url("./myfolder/fonts/Roboto-Regular-webfont.woff") format("woff"), url("./myfolder/fonts/Roboto-Regular-webfont.ttf") format("truetype"), url("./myfolder/fonts/Roboto-Regular-webfont.svg#Roboto") format("svg");
}

[leny]

Hi, thanks for the contribution.

I'm quite busy right now, but I will merged it & publish soon.

Thanks again.