Serd Turtle implementation report

Attached is an updated report for Serd on the latest Turtle test suite.

Since my improvements were rejected, I once again had to manually fix
much of the suite to be able to verify round-trip ttl->nt->ttl
correctness with a streaming implementation and simple text-based
verification.  A diff is attached for reference, but I do not expect it
to be addressed.

One comment/question: The new tests add extended characters in blank
node names, which seems to make round-trip to/from ASCII impossible.
Lack of an escape mechanism capable of doing this is unfortunate.  If
I'm mistaken and there is a way of doing so, I'd like to know how.

As before, the case-insensitive SPARQL prefix/base tests are omitted.  I
strongly protest adding that inconsistent mess to Turtle.

-- 
dr