LOGIC-115: fd/in with singleton domains fails

Change `dom` so that if given a singleton domain we don't bother
adding the domain constraint.
update project.clj for ClojureScript. clean up declares a bit after
running into a ClojureScript declare bug.
update CLJS port so for symbol change. Use non-native type-hint
instead of type specific stuff.
some more not-native type hints. Need to avoid nil punning in
unification of sequential types.
remove set unifiction from CLJS core.logic
we now have explicit failure in CLJS core.logic, no perf hit.
allow `fixc` in the 4 argument case to take a runnable predicate
forgot to fix `fixc` api, we only deal with `-fixc`
allow `fixc` to take rands. x can be a vector values in this case.
treec should take a constriant which checks every node, not just leaves
Merge branch 'master' into entanglement