Implement support for rendering /italics/ properly

[novoid]

This seems to be a tough one: implement support for italics within blog posts without breaking support for determining URLs.

To be honest, I did not spend much time investigating how Org mode is implemented. Maybe there are some clever ideas how to do it properly. So far, I did not do it. Maybe it's easily done.

Ideas for unit tests:

• [ ] determining italics within a line that holds URLs as well
• [ ] determining italics that span over one or even more line breaks (Org mode does it only for one line break AFAIR)

And:

• [ ] add it to https://github.com/novoid/lazyblorg/blob/master/testdata/end_to_end_test/orgfiles/currently_supported_orgmode_syntax.org
• [ ] add documentation to the Wiki

[xeruf]

• I don't think italics in org mode can span over linebreaks
• URLs don't start with a slash, isn't that a clear indicator?

[novoid]

Emacs Org-mode does support italics where a maximum of one line break is in-between. I just tested it via emacs -q

I might not be able to fix this with the current parser. Maybe #63 would be the next chance?