Allow linting from HTML

[rdiez]

I have a small device with a simple built-in web server, so no Linux + Apache etc. The device generates single-file web pages with status information and configuration settings.

I have automated HTML linting inside Emacs: the web page is downloaded first with 'curl', then linted with 'tidy'. The results are displayed in the compilation window, as if they were C++ compilation warnings.

Those web pages have CSS inside several <style> tags, and I would like to lint the generated CSS too.

Unfortunately, csslint cannot lint inside HTML.

I could try to write some script to extract the contents of the <style> tags, but then the position of the warnings (the line numbers) would not match the original HTML file.

It would be nice if csslint could lint the contents of the HTML <style> tags directly.