Make TARGET() table by default for starting tables in JOIN closures

[isuru89]

Currently starting table is mandatory for JOIN closure.

$DSL.select {
    TARGET (Film.alias("f"))
    JOIN (TARGET()) {     // specifying TARGET() is mandatory although by default it can assume
        INNER_JOIN (Film_Actor.alias("fa")) ON (f.film_id, fa.film_id)
    }
}

But it is nice to have make starting table optional, and in case user has not specified it, NyQL assumes it always joining with specified TARGET() table. New equivalent query of above.

$DSL.select {
    TARGET (Film.alias("f"))
    JOIN { 
        INNER_JOIN (Film_Actor.alias("fa")) ON (f.film_id, fa.film_id)
    }
}