move to a predicate-based module system, move to loader.[rs|pl]-based compilation, add support for incremental clause compilation

src/iterators.rs

@@ -481,7 +481,7 @@ impl<'a> ChunkedIterator<'a> {
             }
         }))
     }
-
+/*
     pub fn from_term_sequence(terms: &'a [QueryTerm]) -> Self {
         ChunkedIterator {
             chunk_num: 0,
@@ -490,7 +490,7 @@ impl<'a> ChunkedIterator<'a> {
             cut_var_in_head: false,
         }
     }
-
+*/
     pub fn from_rule_body(p1: &'a QueryTerm, clauses: &'a Vec<QueryTerm>) -> Self {
         let inner_iter = Box::new(once(ChunkedTerm::BodyTerm(p1)));
         let iter = inner_iter.chain(clauses.iter().map(|t| ChunkedTerm::BodyTerm(t)));