Add ability to remove default args via config

[walter]

When trying to use chromic_pdf in combination with pages that contain WebGL images, there are two default args in ChromeRunner that prevent it from working.

• --headless (rather than --headless=new)
• --disable-gpu which, despite its name, will disable software based webgl rendering in addition to hardware accelerated webgl

Based on my experimentation, simply overriding these in :chrome_args is not enough. Once they are declared, they can't be overridden by further switches.

Instead of just taking these out, and maybe break other people's projects, I think adding the ability to remove the args via configuration is a more useful feature.

[walter]

Hi @walter

Had a few stylistic nitpicks still. If you don't want to continue working on this, I can also merge it in and refactor afterwards. As you prefer.

Thanks again!

Thanks for the feedback. Jibes with some thoughts I had myself, but was distracted by other work. I hadn't used List.wrap before, nice!

Have a look at latest and let me know if there is anything else.

[maltoe]

Thanks again!

[maltoe]

Released as v1.16.1