#85 query parser can't handle namespacing

[J Carletta]

NXT should allow data elements and attributes to be namespaced,
since different groups may want to provide rival annotations of what
is basically the same linguistic phenomenon, and it would be a pain
for them to avoid naming conflicts without it.

The query parser currently treats every colon (:) as a query separator,
and therefore can't handle namespacing at all.

The workaround is (1) use the query language functions to handle
anything that is by default in the nite namespace (e.g., ID($x), not
$x@nite:id) and (2) avoid any further use of namespacing. Not ideal,
though.