Add Italics style

[alerque]

This is a rebase of @cssobral2013 #22 with the only thing that matters: the source. Unfortunately since that PR was opened from the owner's master branch I can't help directly by editing the PR.

It isn't building properly yet so let me take care of whatever that is about, then I'll comment with instructions on how to either get this moved over there or whatever needs to be done next...

[cssobral2013]

@alerque - I cannot test it now because I use Windows, so I cannot use Glyphs.

[alerque]

Thanks @cssobral2013. I'm in much the same boat being on Linux. I've tagged both your original PR and this on as help wanted and would encourage anybody who is interested in taking this on to drop a comment and I'd be glad to help work through the process. But we do need somebody with Glyphs and a working knowledge of it.

Eventually Fontship should facilitate the process of contributing to fonts using any editor by providing conversion between source formats, but that bit is under-developed right now.

Additionally this PR should be building the Italic font as ready to use binary artifacts that anybody could test, but there is a syntax problem with the Glyphs file. Until that is worked out we can't even really preview how this would fit in.

Again to anybody interested in helping, please drop a line here and I'll help you get rolling.