Adding support for 1.6.x

A lot of code was effected by the lightweight edges feature and the splitting of edges across multiple in/out properties based on edge class. In order to maintain backwards compatibility, I've peppered the code and tests with a lot of version checks...

    if (server.manager.serverProtocolVersion >= 14) {

I'm sure version 14 is the correct cutoff for most of the checks, but there were a couple tests I modified in my last commit in which I wasn't certain. And I wasn't motivated to test against every release between 1.3.0 and 1.6.3.

Behavior has changed for GraphDb functions getOutEdges and getInEdges in order to support lightweight edges. When lightweight edges are encountered, it returns the corresponding vertex object rather than an edge object that has no _@_rid. It might be helpful to add an option parameter to these functions to exclude vertex objects.


58/60 tests are passing for both 1.3.0 and 1.6.3. The failing tests are...
<table>
  <tr>
    <td>test_date.js</td><td>failing in 1.3.0</td>
  </tr>
  <tr>
    <td>test_lh_cluster_used.js</td><td>failing in 1.6.3</td>
  </tr>
  <tr>
    <td>test_positions.js</td><td>failing in both</td>
  </tr>
</table>

I don't know why test_date.js is getting the wrong day (20 vs 21), and I don't understand what the other two tests are for or the results they are getting.

oops. Just noticed that I committed my change to serverConfig.json. I hope that isn't a problem.