Change font family, fix invalid CSS (fixes #70)

[niutech]

CSS values image-rendering: optimizeSpeed and optimize-contrast are invalid, as are // single-line comments.
Now with font-family: 'Courier New', monospace a web page text fits its background image (issue #70).

[tobimensch]

@niutech
Thanks for your pull request.

Through the linked issue it appears you're using "Windows 10 with devicePixelRatio=1.25".

Did you test your patch with any other system, i.e. Linux?

[niutech]

No, right now I have only Windows 10 machine, I will test it as soon as I get to the Linux computer.
Meanwhile I have edited the PR not to change the font-size, but to use Courier New font if available, because it fixes the issue with font width (default monospace on Windows 10 is Consolas, which is narrower).

[tobimensch]

@niutech
You probably know this, however I just wanted to mention that you could also test this in a Linux virtual machine on Windows.

[niutech]

Yes, I'll post some screenshots when I test it in Linux.

[niutech]

OK, I have tested the changes under Lubuntu Linux. Here is Chromium with default monospace font:

Here is Chromium with 'Courier New' font:

And here is Firefox with the new font:

The new font does not break page layout nor change font size on Linux, but it fixes the layout on Windows 10, so I propose to merge this fix.

As a side note, I think the default width (number of columns) on html.brow.sh is too narrow for today's screen sizes. I would increase it to 140.

Thanks!

[tombh]

Thanks so much for this, for doing the research, finding a fix and submitting the screenshots. I'm happy to merge this. Just one thing, but don't worry if you don't get round to it, could you squash these 2 commits and just create a little commit message giving the context to these changes.

[niutech]

You can easily squash commits by yourself while merging: https://github.blog/2016-04-01-squash-your-commits/

[niutech]

@tombh Will you merge this PR?

[tombh]

Sorry for the delay. By asking you to rebase I was hoping you'd be able to better name and describe the commit. Then I just forgot about it.