Add [gloref] to fdoc.

Links to /share/src/web/ref/glossary.fdoc#gloref.
Not very general, and Felix website specific, not so nice
for such a general micro-coding as [..] but its start.
Merge remote-tracking branch 'origin/master'
Merge branch 'shayne'
Attempt to fix unused parameter bug.

Not sure if this works but it fixes test case.
Merge branch 'master' of github.com:felix-lang/felix
Merge branch 'shayne'
Merge remote-tracking branch 'origin/master'
Merge branch 'shayne'
Merge branch 'shayne'
Try to fix tre/unordered_set issue.

Copying hackery from Google RE2 Mercurial source
for their solution.
Revert index.
Copy includes file with header. Use match in tutorial.
Fix small mistake