Improve newline handling

[bytestream]

• Removed new line normalisation which converted \n{3,} to \n\n - previously behaviour was frankly a hack to handle improperly outputting LFs to begin with
• Improved padded paragraph (<p>&nbsp;</p>) handling, output now matches that of a browser
• Added lf-per-block option which allows you to control how many LFs are output. For example, if you have p { margin: 0 } then lf-per-block => 1 correctly matches the browser output
• Corrected parameter mismatch in assertEquals usage (assertEquals($output, $expected); should be assertEquals($expected, $output);)

Closes #94

[edgrosvenor]

@bytestream I haven't looked at this because it's still marked as a draft. I'll be doing some work on this package this weekend, so if this PR is ready to be reviewed and maybe merged in, let me know. Thanks!

[bytestream]

@edgrosvenor I was having a hard time getting the implementation to work in the context of this lib; every change would break a test. I ended up writing my own implementation and copying over the tests.

I'll close this and the associated issue given it's perhaps niche.