textContent Checking
I have added checking of the textContent of the meter, progress and t elements to the conformance checking service technology preview. The textContent is checked if meter or progress does not have an attribute called value or if t does not have an attribute called datetime.
I took liberties with date formats. Also, I am assuming that it is an error if the algorithm for finding a ratio fails.
I have also made the error messages prettier. Additionally, there is now a pseudo-schema called http://hsivonen.iki.fi/checkers/debug/ which dumps the parse events as warnings. (It makes the most sense when used as the first schema URI on the list of schema URIs.)
The t element has been renamed to time and x to t.