Accept HTML Whitespace in Parser Tags

[HeRaNO]

Allow the LiteParser tag patterns to recognize CR, tab, and form-feed as whitespace [1] between tag names and attributes. This fixes serialized HTML with CRLF line breaks inside tags, such as output generated on Windows.

[1] https://infra.spec.whatwg.org/#ascii-whitespace

[HeRaNO]

@dpvc Hi! Would you please consider this PR? ASCII whitespace will affect the tag parsing on the Windows platform.

[dpvc]

@HeRaNO, your PR arrived last Friday morning while we were putting together the v4.1.3 release. This weekend was the 4th of July holiday, here, so not much got done during that. I was planning to discuss your PR during our weekly developers' meeting on Thursday.

Pinging us after three days (and those being over a holiday weekend) is too soon. We are aware of your PR and the issue you present (and the new post on the issue tracker), and will process it in due course as we are able. Reminders are not necessary, and actually slow down the process (e.g., I have to take time to write a response like).

Patience is a virtue.

[dpvc]

Thank you for your contribution.