Fix ordering issue in vector_orddict

[define-null]

In the current master vector_orddict:insert function would compare all dots for >, rather then >=, which will lead to a wrong ordering of vv, such as: if given
#{dc1 => 1, dc2 => 1} and #{dc1 => 1, dc=> 2}, the vector_orddict internal ordering would be dependent on the insert order, and vector_orddict:first would give different results.

[define-null]

Let's wait till AntidoteDB/antidote#488 is reviewed. Maybe there are more places that should be fixed while we are on it.