filter_tags() or equivalent should include partial tags in its results

[TheSandDoctor]

@earwig It would be useful for stripped tag identification and handling if filter_tags() or a new equivalent function (like filter_all_tags() or something) would also include partial tags in its results. These issues/errors could be run across anywhere and thus the current way of ignoring them provides potentially inaccurate results. Is this change possible?

Currently, <span color="0000">test</span><font color="red"> will not find <font color="red"> as it isn't closed.

I foresee this change potentially happening through the following sequence:

1. a new property is added to the Tag class to identify if it is incomplete (could then be closed by user)
2. filter_tags() is either updated to include or a new function created

(I am not off-hand sure how it would be made after looking at the code base, hence my asking your assessment as your wrote the package.)

Thank you for your time.