Support out of order SQL query chaining

[yojimbo87]

Support out of order chaining, e.g. user can do

Create.Vertex(fooDoc) .Cluster() .Run();

and it will generate

CREATE VERTEX Foo CLUSTER Bar SET foo = 1, bar = 2

instead of

CREATE VERTEX Foo SET foo = 1, bar = 2 CLUSTER Bar

[yojimbo87]

Update(doc)

Insert(doc)

Create.Vertex(doc)

Create.Edge(doc)

Maybe Set methods should serve only to save single K/V pairs and not entire documents.

[yojimbo87]

Done @ v0.2.0