67 shortest path bounded

[SiberiaWolfP]

Fixes #67 and #94.

Now bounded length query like:

-FROM GRAPH_TABLE (pg4
    MATCH
    p = ANY SHORTEST (a:Point4)-[k:know4]->{2,3}(b:Point4)
    COLUMNS (a.id, b.id, vertices(p))
    ) tmp;

will look for the shortest path between the source and the destination with a length between 2 and 3. To disambiguate, the effect of this syntax is consistent with choosing the shortest path between the upper and lower bounds after finding all possible paths between two nodes.