to a DBLINK remote database; while the syntax has been present in the
Oracle dialect for some time, up until now it has never been tested.
The syntax has been tested against a sample database linking to itself,
however there's still some uncertainty as to what should be used for the
"owner" when querying the remote database for table information.
Currently, the value of "username" from user_db_links is used to
match the "owner".  [ticket:2619]

could be lost if the statement were used as a subquery
inside of another statement, as well as other similar
situations.  Among other things, would cause
typing information to be lost when the Oracle/mssql dialects
would apply limit/offset wrappings. [ticket:2603]

- build a new Sphinx extension that allows dialect info
to be entered as directives which is then rendered consistently
throughout all dialect/dbapi sections
- break out the "empty_strings" requirement for oracle test

- begin consolidating docs for dialects to be more self contained
- add a separate section for "external" dialects
- not sure how we're going to go with this yet.

    will now schema-qualify the name of the index
    to be that of the parent table.  Previously this
    name was omitted which apparently creates the
    index in the default schema, rather than that
    of the table.